Mr Johnson is travelling to Liverpool

The Spectator editor, who is also Tory culture spokesman, is due to travel to the city to apologise in person.

An article in the magazine suggested grieving Liverpudlians were wallowing in their victim status.

It also attributed blame to drunken Liverpool football fans for the 1989 Hillsborough disaster in which 96 died.

'Misrepresenting'

Now - in a letter to the Liverpool Daily Post - Mr Johnson says: "I am sorry, too, for the hurt and dismay we have so evidently caused in our description of Liverpool.

"There may well be Liverpudlians who still answer to the characteristics in question, just as there are all over the country. We should not have generalised.

"And we should clearly not have blamed drunken fans at the back, when this cause was specifically ruled out by the inquiry report.

"Anyone, journalist or politician, should say sorry to the people of Liverpool - as I do - for misrepresenting what happened at Hillsborough."

"I repeat that the leader [Spectator leading article] made a serious point about risk and sentimentality, and the culture of blame, and I stick by it. In so far as it imposed an outdated stereotype on the whole of Liverpool, and thereby caused offence, I sincerely apologise."

Beheaded

Ahead of his visit betting chain William Hill said some punters were backing Mr Johnson to become prime minister, on or before 31 December 2014, at odds of 66/1.

The bookmaker is also quoting odds of 25/1 on him becoming the next Tory leader.

"We have been a little surprised to take several bets for Boris both to lead his Party and the country in recent days," said a spokesman.

Party leader Michael Howard told Mr Johnson to go to Liverpool saying his article was "nonsense from beginning to end."

Mr Bigley was beheaded by the Tawhid and Jihad group, led by Jordanian militant Abu-Musab al-Zarqawi earlier this month.

He had been kidnapped while working in Iraq.