The BBC's Carolyn Quinn explains the concerns about Lord Archer

Sir Timothy Kitson, a former parliamentary aide to Sir Edward Heath, says questions of integrity need to be sorted out before a candidate for mayor of London is chosen.

Lord Archer is believed to be a frontrunner for the Tory mayoral nomination.

Sir Timothy has filed his complaint to the party's new ethics and integrity committee.

His correspondence has been sent to the party chairman, Lord Parkinson, setting out that the allegations involving Lord Archer need to be answered if the party is to avoid possibly repeating the mistakes of the last general election when issues of probity dominated the headlines.

His letter raises claims made against Lord Archer in a biography written by BBC journalist Michael Crick.

The book, entitled "Stranger Than Fiction", covers Lord Archer's alleged missing A-level and university degree certificates, his resignation as an MP and a gift of £2,000 to a prostitute he had never met.

The book also draws attention to a Department of Trade and Industry investigation in 1994 after Lord Archer purchased shares in Anglia Television, of which his wife was a non-executive director, shortly before they leapt in price.

In his letter Sir Timothy says: "The allegations raise questions that should be answered before the Conservative Party selects its candidate for the mayor of London."

Should this committee sit it will be the first time the Conservative Party has sat in judgement of one of its own members.