He scored 21,470 votes to Mr Wong's 21,527. Dr Tang said last night he thought he had been unfairly treated and demanded an explanation from the authorities.

He said he would take a short break before meeting campaign workers to decide whether a formal complaint should be filed.

'I feel that the situation is unfair to me and the Government should give me a clear explanation of what happened,' said Dr Tang.

He insisted his supporters had not moved out of the district and there was no reason for them to check that their names were on the electoral register.

He believed the unofficial figures amounted to about 1,000 people who were denied the right to vote. Polling station staff estimated only a few hundred residents were affected.

Boundary and Electoral Commission chairman Mr Justice Woo Kwok-hing said the commission had received no complaints from candidates about the outcome of the poll, but said any such complaints would be investigated.

He said 110,000 names had been dropped from the register after updating between January and March.

Two other veteran politicians who suffered defeats - Elsie Tu and Peggy Lam Pei Yu-dja - were nursing their wounds in private and declined to talk to the press.

Mrs Tu, 82, lost by 29,627 to 23,855 to Szeto Wah in the Kowloon East constituency, where she also lost to him in the Urban Council poll in March.

But Mrs Tu's husband, Andrew Tu Hsueh-kwei, made it clear his wife would not stop serving the community.

He said she would set up a new office in Kwun Tong to handle complaints by the public.

Asked whether his wife was unhappy about the result, Mr Tu said: 'There's nothing we're unhappy about.' Mrs Lam, beaten by independent Christine Loh Kung-wai by 27,199 to 14,437 in Hong Kong Island Central, refused to talk to reporters at the vote-counting centre after the result was announced.

Mr Justice Woo said the delay in vote-counting and the announcement of results were due to a mismatch between the number of ballot papers issued and those collected in the sealed box.