Manager Sam Allardyce accepts that even a new contract would not be enough to prevent him being sacked should results go badly at the start of next season.

Allardyce, 58, looks set to tie his future to the Irons with a contract extension once the east London club have secured their Barclays Premier League status again following an impressive return to England's elite.

However, the former Bolton, Newcastle and Blackburn boss, whose side tackle champions-elect Manchester United at Upton Park tonight, remains pragmatic about the ups and down of a football manager.

"There is another stint I am looking forward to here, hopefully, which will get sorted out once we have made sure of our Premier League status," he said.

"But beyond that I could get sacked in six months next season or less. If results don't go our way and we start the season poorly, then I am more likely to get sacked than stay here for the period of the contract.

"That is life in football now. If you accept it then you can deal with it.

"The highs and lows are massive for a manager, you have got to be able to manage it and be big enough to deal with it.

"You strive to make sure you don't have too many lows and you have as many highs as you can. That is why you drive yourself and everybody else forward.

"Yet however well I have or haven't done, I am never satisfied. I want to do better. I am a pain in the arse to the owners, because I have never got enough money and I have never got enough players.

"That is just the way I am and sometimes perhaps they feel that's little bit difficult to live with, but that is me.

"It is me driving that ambition of myself and the club forward."

The Red Devils could stretch their lead at the top of the table to 18 points with victory tonight, taking them within touching distance of the title once again.

Allardyce believes the way United have gone about wrestling back superiority from rivals Manchester City has been awe inspiring.

"I think you have to say the (United) team is as good as it has ever been because nobody normally wins the title so easily and by so big a margin, or has this much of a margin at this stage of the season," said Allardyce.

"It is pretty scary what total they might actually finish with. Manchester United have been outstanding.

"They have not had the normal focus on three or four competitions almost to the end, the focus has come on the Premier League and they have just breezed it.

"They have just gone 'bang' and everyone else can't get near them."