Amid rowdy scenes in the Commons yesterday Stephen Byers denied misleading parliament when in February he announced the resignation of his department's communications director Martin Sixsmith.

Earlier this week, the department of transport issued an agreed statement that Sixsmith had not resigned.

Speaking in the Commons amid calls for his resignation, Byers claimed that his earlier statement - entitled "the resignation of Martin Sixsmith" - was given "on what turned out to be an incorrect understanding of earlier discussions that day."

However, Tories called for the transport secretary to quit, and are expected to call him back to the Commons for a censure motion in the next fortnight.

Their call was backed yesterday by former Northern Ireland secretary Mo Mowlam, the Times reports.

The row coincides with an FT interview with Railtrack chief executive John Armitt, in which he says that billions of pounds of taxpayers money will be needed over the next five years to improve the state of Britain's railways.