"At fault is the way Ma dealt with this obviously political power struggle by accusing Wang of influence-peddling," said Hou Han-jyun, associate professor of public administration and policy at Taipei University.

An indignant Ma, in his capacity as KMT chairman, demanded that Wang, 72, stand down as president of the Legislative Yuan on Wednesday. Hours later, the KMT's disciplinary body revoked Wang's membership, costing him his seat in the legislature.

But Wang has fought back, with the Taipei District Court yesterday granting him an injunction against his expulsion.

Wang enjoys broad support in the legislature, helped by his status as a native rather than a more recent immigrant. He hails from Kaohsiung, the southern city that is the power base of the opposition Democratic Progressive Party and the hotbed of Taiwan's pro-independence movement. He has served as Speaker since 1999.

Analysts see Ma's move as an attempt to warn other lawmakers who have been reluctant to embrace the government's agenda. The Legislative Yuan has stalled in passing a bill to hold a referendum on a fourth nuclear plant and a new cross-strait trade deal agreed with Beijing in June has not yet been endorsed despite two extraordinary legislative sessions devoted to it. Beijing is said to be becoming increasingly agitated at Taipei's failure to approve the pact.

But the early signs are that the legislature will turn against Ma, whose approval rating has slumped to a record low of just 11 per cent, according to a poll from TVBS television.

"The Ma government is set to see its operations further hindered by the stalling or failure of the legislature to pass major bills," said Hsu Yung-ming, associate professor of Soochow University. Wang's sacking was Ma's attempt to "remove the stumbling rock that obstructs him from pushing through the bills".

Gao Jyh-peng, head of the DPP caucus in the legislature, said his party had joined its smaller ally the Taiwan Solidarity Union and other, independent legislators to stop Premier Jiang Yi-huah delivering his administrative report at the opening of the new legislative session on Tuesday.

The Union has also launched a campaign to remove Ma, and the DPP is considering joining it.

While the opposition is unlikely to block the government budget, it is likely to force through cuts in several areas of spending amid the backroom horse-trading that accompanies the annual budget-setting process.

The opposition is also drafting a bill to abolish the Special Investigation Division, which sparked the scandal when it recorded a conversation between Wang and opposition lawmaker Ker Chien-ming in a breach-of-trust case.

Gao said the division had "become the secret police for Ma to spy on his opponents".

Analysts say Ma's attitude towards Wang has been markedly harsher than his treatment of close aides charged with bribery or a KMT magistrate accused of improper lobbying.

Three days before Wang's removal, and without presenting direct evidence or going through any judicial process, Ma insisted Wang was guilty of lobbying judicial and prosecution authorities not to appeal against the High Court's acquittal of Ker.

The accusation, made while Wang was attending his daughter's wedding in Malaysia, was seen as part of a naked power struggle with Wang, who unsuccessfully took on Ma in the first direct election for the KMT chairmanship in 2005.

Wang Kung-yi, of the Graduate Institute of International Affairs and Strategic Studies at Tamkang University in Taipei, said Ma hoped to warn other legislators who have defied him.

"Though Wang has insisted that, as a Speaker, he must remain neutral, Ma has suspected Wang is actually siding with the DPP, as evidenced by his failure to help push for the passage of the cross-strait services-trade agreement," Wang Kung-yi said, referring to the trade deal with Beijing.

"With such a low approval rating, Ma hopes he can do something before he steps down in 2016. As cross-strait relations would be something that could allow him to leave a legacy, it is understandable Ma is putting more effort in this area," he said.

But Taipei University's Hou said Ma was not only risking the wrath of the legislature but also challenging the constitutional separation of powers.

"While his political manipulation is far from sophisticated, Ma's interference in a judicial matter and breach of the separation of powers of the legislative and judicial branches has also triggered a constitutional crisis," he said.

"Without substantive proof or direct evidence, Ma's assumption that the Speaker was guilty of lobbying contradicts the principle that everyone is presumed innocent if not convicted," KMT lawmaker Lee Te-wei said.

Fellow legislator Hsiao Ching-tien warned that the sacking of Wang would trigger a wave of defections by long-time KMT members and a backlash from Wang's supporters, as well as problems in the legislature.

"It will not only affect next year's municipal government elections, but also the presidential election in 2016," Hsiao warned.

Ma cannot run again. But a split in the KMT allowed Chen and the opposition Democratic Progressive Party to win power in 2000, ushering in an era of tumultuous relations between Taipei and Beijing.

On Monday, Jiang, the premier, admitted that a period of political instability and chaotic sessions in the legislature were likely should Wang be sacked.

Since Wednesday, the switchboards at KMT headquarters have been besieged by thousands of callers angered by Ma's treatment of Wang. In southern Taiwan, 11 community leaders quit the party, saying they would urge others to join them.

"I don't understand how Ma could be so heartless and cold-blooded after Wang had helped him for many years," said one community leader who quit the party.

Local news media have described the turmoil as a political soap opera with all the drama needed to keep television audiences hooked.

It all started in late June when prosecutors of the Special Investigation Division carried out wiretaps while investigating Ker, the DPP whip in the legislature.

The investigators claimed they "accidentally" overheard Wang talking to Ker about the breach-of-trust case. Ker asked Wang to lobby then justice minister Tseng Yung-fu and ask that no more appeals be brought against him. Ker won an appeal in the High Court after being found guilty and sentenced to six months in prison or a fine of NT$180,000 (HK$47,000).

According to transcripts of the wiretaps, Wang called Ker on June 29 and told him "it's all OK". The July 8 deadline for an appeal to be filed passed with no action from prosecutor Lin Hsiu-tao.

On August 31, with the investigators unable to find any direct evidence against Wang and Ker, they summoned Lin and asked why she did not file an appeal. Lin said Chen Shou-huang, head of the High Prosecutors Office, had told her "not to waste judicial resources" and cited budget constraints.

The investigators concluded that Ker had first sought help from Chen but, fearing he would not prove powerful enough, then asked Wang to use his influence on Tseng.

The investigators ordered Lin to keep silent about the case and passed their information to prosecutor general Huang Shih-ming.

As a typhoon raged, Huang made his way to Ma's home to brief him on the alleged lobbying and show him the transcripts.

It took until September 5 for the investigators to refer the case to the Control Yuan, effectively the state auditor, to consider impeaching Tseng.

The next day, as Wang flew to Malaysia for his daughter's wedding, the division held a news conference and released the wiretap transcripts, accusing Tseng, Chen, Ker and Wang of influence-peddling.

But it was unable to show any contact between Wang and Tseng, or between Tseng and Chen.

Because no financial bribes were involved, criminal charges could not be brought and the division could only refer the case to the Control Yuan.

Chen's case was sent to the disciplinary committee of the Justice Ministry.

As the Legislative Yuan is an independent body with its own rules, the division said it was up to lawmakers to deal with Wang and Ker.

An indignant Ma held a news conference on Sunday, blasting Wang for what he called the "most serious infringement of Taiwan judicial independence" and the "most shameful day in the development of Taiwan's democracy".

He said of the Speaker's actions: "If it is not lobbying, then what is it?"

Jiang followed suit, questioning Wang's credibility and suggesting he should quit.

On his return to Taiwan on Tuesday, Wang set out his side of the story. He claimed to have told Tseng only to abide by a legislative resolution that no unnecessary appeals be launched to avoid wasting judicial resources.

The people of Taiwan seem to be on his side, with 55 per cent of respondents in the TVBS poll finding Ma's actions unacceptable, while just 17 per cent supported his decision.

But while Wang resumes his duties when the legislature meets on Tuesday, the consequences of the row for Ma and for Taiwan could be felt for some time yet.