Mr McLetchie has been under relentless pressure after it was revealed he had spent £11,500 on taxis, more than any other MSP, during the first five years of the Holyrood parliament.
Details of those taxi claims suggested he had been reimbursed for trips he made on party or personal, rather than parliamentary, business, some of which were to the Edinburgh legal firm where he worked at the time.
Although the Edinburgh Pentlands MSP, who has constantly criticised ministers for their "waste and extravagance", said the claims had been made in good faith, he repaid £250 which he said had been misclaimed for a flight to Bournemouth in 2002 and a trip to Selkirk in 2003.
However, intense media and opposition pressure continued, with further allegations of "misclaimed" trips, until Mr McLetchie announced yesterday he was standing down with a "heavy heart" as he recognised the media coverage was damaging the party.
The move came in the wake of a survey of 59 Scottish Tory constituency party chairmen which showed that more than a third wanted him to resign. Less than two years away from the next Scottish parliamentary elections in 2007, many of the party's local hierarchy believed the "taxigate" row was a major distraction from the party's efforts to rebuild its support north of the border.
"I have today tendered my resignation as leader of the Conservative group of MSPs in the Scottish Parliament. I do so with a heavy heart, as it has been both an honour and a privilege to lead the group for the last six years," said the lawyer-turned politician who took on the leadership in 1998.
"I recognise that the recent coverage surrounding my expense claims has been damaging and is a major distraction from our efforts to rebuild support for the party in the country. Accordingly it is right that I stand down as leader."Reuse content