Taiwan is a hypersensitive issue for Beijing – especially US arms sales and increasing official exchanges with Washington, which does not have formal ties with Taipei.

A mainland-based political analyst familiar with Beijing’s thinking said the priority was to avoid any major disruption to the US relationship ahead of the party congress.

“China-US ties cannot deteriorate further and that was the tone set by the party before [Pelosi’s potential Taiwan trip was reported],” said the analyst, who did not want to be named due to the sensitivity of the matter. “Beijing has grave concerns about the situation escalating, especially in the event of an accidental conflict.”

What US-China row over Pelosi and Taiwan means for Asian region

George Magnus, an economist and research associate at Oxford University’s China Centre, said Beijing and Washington were in a tough spot.

“[Pelosi’s] purported visit to Taiwan is clearly seen by China as throwing down a gauntlet, and by the US as the weaponisation of simply a trip by a senior politician,” he said. “They both seem to feel an obligation to react, and resist, respectively.”

Magnus said Xi would “want to appear in control and firm in his handling of what is regarded as a provocation” in the face of domestic and external challenges when he was seeking another term at the party congress.

“Although I think it is unlikely that his renomination as head of state and the party is seriously at risk, failure to be seen to stand up to the US could undermine his status and freedom of manoeuvre, and might encourage his opponents now or in his new term.”

Shi Yinhong, an international relations expert at Renmin University, did not expect any retaliatory measures taken by Beijing to lead to military conflict.

“Despite the more ominous indications, the fundamental situation of the Taiwan problem should be regarded as largely stable at its bottom,” he said. “They have established quite firmly … each side’s bottom line and would be convinced that military conflict must be avoided absolutely until or unless it would be required absolutely.”

But Shi expected bilateral ties to worsen, and said “the possibility of accidental conflict has gone up significantly”.

For Beijing, the best-case scenario would be if Pelosi cancels the trip.

“It would be a major victory for Xi because he could claim the credit for successfully deterring the visit and reaffirming a bottom line on the Taiwan issue – that people like Pelosi aren’t allowed to visit,” said Deng Yuwen, a former editor at the Study Times newspaper, a party mouthpiece.

But even if she does go, it is likely to be an unofficial trip – and that would be a win for Beijing, according to Alfred Wu, an associate professor at the Lee Kuan Yew School of Public Policy at the National University of Singapore.

“Nationalism and support for Xi in China is stronger than ever before. Ordinary Chinese people feel that Xi is strong as he can manipulate the domestic propaganda into a narrative that he has scared the US and what might have been an official visit was changed to an unofficial one,” he said.

Wu said Beijing would try to avoid an overreaction that risked a military conflict with Washington just months ahead of the party congress.

“What Xi wants is a narrative that shows China is stronger than the US and that he’s in command – this is what Beijing wants,” he said. “Everything in China now is related to [Xi’s bid for] a third term and it is the top agenda. Xi will shout louder in condemning the US to show the domestic audience that he is strong.”

China puts on show of naval force ahead of Pelosi’s possible Taiwan visit

Dali Yang, a political scientist with the University of Chicago, also said that while a Pelosi visit could worsen tensions with Washington, it may not be bad news for Xi.

“An external challenge usually helps the party to strengthen its military and emphasise the party’s leadership, and it helps the cause of leaders with a nationalistic and a reunification agenda,” he said, adding that Xi would have to “keep the situation under control”.

Yun Sun, a senior fellow at the US-based Stimson Centre, said despite Beijing’s threats of using military force, the priority was stability in the lead-up to the party congress.

“[A Pelosi visit] will not endanger Xi’s plan [to stay on for a third term] as long as a war doesn’t break out,” she said. “It is embarrassing for him, but instability will be a bigger risk factor for him at this point.”

If the trip does go ahead, Beijing could react by firing missiles in Taiwan’s direction and sending more warplanes near the island, according to Gal Luft, co-director of the Washington-based Institute for the Analysis of Global Security.

But he said there was no reason for China to overreact. “Xi is the most powerful leader since Mao – why would he have to even react to this?” Luft said.

“To be sure, the party apparatus will try to capitalise on such a visit, but an overreaction to a visit of an octogenarian who will soon be kicked out of her job as speaker … will only be a sign of insecurity, inviting more of the same,” he said.

“Self-confidence is the ability to exercise restraint in the face of provocations and disrespect. The world knows the purpose of the visit is provocation. What it is yet to determine is whether China is a confident superpower or an insecure and easily rattled wannabe.”

Additional reporting by Amber Wang and Jun Mai