London - British Prime Minister Gordon Brown on Monday wrote personal letters to opposition political figures named in emails at the centre of a smear row which caused the resignation of one of his top advisors. Damian McBride, a former aide to Mr Brown in 10 Downing Street, quit his job over the weekend, after emails he sent in January suggesting possible smears of the top Conservative politicians were leaked to an internet blogger.

Facing demands for a public apology, on Monday Mr Brown wrote "personal" letters to at least three of the opposition figures named in the emails, and said he would tighten up rules governing civil servants code of conduct.

McBridge was formerly the prime ministers press advisor and strategy consultant.

Emails containing slurs about the mental health of a top Conservative politician's wife, and the alleged ex-marital affair of a female lawmaker, among other rumours, were initially dismissed as "juvenile" by Downing Street.

But as the political row grew, McBride was forced to resign, and Mr Brown was facing serious questions about his judgement and calls for a public apology.

It is not the first row to embarrass the prime minster recently. The husband of the home secretary, Jacqui Smith, was recently caught claiming for pornographic movies from taxpayer expenses.

One Conservative parliamentarian was said to be considering legal action over the emails.

Mr Brown, who took over from Tony Blair in 2007, is lagging far behind in opinion polls, and must call an election by next year at the latest.(dpa)