Boris Johnson, the Mayor of London, may say farewell to the Commons next month as the Conservatives move swiftly to stage a by-election in his Henley constituency.

David Cameron’s party has pen- cilled in June 26 or July 3 as the most likely dates for a contest, in an attempt to capitalise on its revival in this month’s council elections.

Mr Johnson promised to give up his seat for Henley-on-Thames during the campaign to replace Ken Livingstone, although he had not been expected to do so until the autumn at the earliest.

Senior Tories say that Mr Johnson has told the leadership that he believes he should leave the Commons as soon as possible to concentrate on his new job. Party strategists also want to move quickly to prevent the Liberal Democrats, second in the constituency in 2005, securing a foothold.

Mr Johnson had a 12,000 majority at that election and it would be a substantial shock if the Conservatives failed to hold it.

The Liberal Democrats have chosen a candidate and the Tories will pick theirs as soon as the writ for the by-election has been moved, which will be the week after next when the Commons returns from spring recess.

As voters went to the polls in the Crewe & Nantwich by-election, Gordon Brown prepared for a meeting with the Dalai Lama today. Afterwards he will travel to Scotland for the Bank Holiday weekend, which sends out the signal that it will be business as usual in the weeks ahead.

Early indications last night from Crewe & Nantwich were that Labour was on course for a heavy loss at the hands of the Conservatives.

Hazel Blears, the Communities Secretary, said last night on BBC Question Time: “It might be that the electorate have decided to send us a pretty powerful message but the last thing they want is the Labour Party to turn on itself and be obsessed with our own affairs and not what the public want.”

Despite the mauling in the local elections this month, most MPs believe that Mr Brown faces no serious challenge to his leadership at this stage. However, they also say that he is on trial and will need to make headway before the conference season.

In the the past month, there has been a remarkable turnaround in Mr Cameron’s political fortunes. Less than a year ago, after a party row over grammar schools and a mistimed visit to Rwanda during the summer floods in Britain, he was trailing in the polls.

This month, Labour suffered its worst electoral performance for 40 years in the local elections, pushed into third place behind the Lib Dems, while the Conservatives took control of London with Mr Johnson.

The Crewe campaign had a late twist when the Conservatives admitted sending personal information on 8,000 voters to a radio station by mistake. But there were accusations of dirty tricks yesterday after the Tories discovered an automated message was urging voters to phone their campaign headquarters, jamming the number used by those who wanted help getting to the polling stations.

A Labour official said that he was unaware of the message but was unable to deny that the party was responsible.

— Boris Johnson has appointed Tim Parker, a private equity manager, as chief executive of the Greater London Authority. Mr Parker, said by unions to have a reputation as an asset-stripper, will also be in charge of transport. He will not take a salary and will step down from all business interests.

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