Mr Lan last night described reports about him running for a seat as 'speculative' and refused to confirm or deny them. However, he said claims Mr Lo had acted as the middleman for him to join the alliance were 'nonsensical'.

Mr Lau said: 'Nobody has ever interfered with our electoral affairs. Every arrangement and negotiation of candidacy is made by the alliance. As far as I know and what I have heard from members of the alliance, Mr Lan would not join our membership or the alliance's ticket to run [in the Legco polls].'

He said regional office chairman Choy Kan-pui would head the three-candidate alliance list. Mr Choy, who will submit his nomination today, said he did not know Mr Lo personally.

Mr Lau admitted difficulties in arranging for a new member to run. 'As the deadline for nominations is approaching, I think it is very difficult for us to add a new member on our [election] ticket within such a short period. I think this is impractical.'

A Civil Service Bureau spokesman said civil servants were not allowed to run for election unless they had resigned. Mr Lan is still a civil servant while taking pre-retirement leave.

Dr Law Cheung-kwok of the New Century Forum submitted his nomination for the constituency yesterday. Dr Law, a former legislator and ex-vice-chairman of the Association for Democracy and People's Livelihood, believed his expertise in the economy would appeal to voters.

Nominations close on Wednesday.