London Mayor Boris Johnson is still refusing to name the date when he will step down as MP for Henley.

Speculation is mounting that the Tories are about to call a by-election for the seat in the last week of June or first week of July - particularly after the party's big win in Crewe and Nantwich last night.

That will mean Mr Johnson, who beat Ken Livingstone in the capital's mayoral vote earlier this month, formally resigning his parliamentary seat within days.

But this morning Mr Johnson was still batting off questions about when that will be.

He was speaking at Wheatley Primary School to promote walking and cycling to school morning.

He said: "Something will come up in due course but I have to speak to the Conservative Association about it first."