Ferguson: Arsenal have been in fantastic form (StuForster/Allsport)

With just matches games remaining and Arsenal holding a four-point lead, Ferguson cannot envisage either Manchester United or Liverpool stopping Arsene Wenger's side.

Ferguson had hoped Arsenal would have slipped up by now, but even he grudgingly admits they deserve credit for their recent incredible run.

The United manager can only stand back and admire the way Arsenal have strung together 10 consecutive league wins since the start of February to put themselves in pole position.

United could peg Arsenal back if they win their showdown at Old Trafford on May 8, but Ferguson knows that alone will not be enough to prevent them relieving his team of the Premiership trophy.

'You can't really see them slipping up because all the times you expected them to drop something, they've come up with the answer and you have to give them credit for that,' he said.

'They look in an unassailable position now. Our form since Christmas has been very good, but equally so Arsenal.

'They have been in fantastic form and you can't really see them losing now because they are in such a strong position.

'For Liverpool, too, if we were to beat Arsenal they could win the league so it's an exciting time for them too. We can only do our job and see what happens.'

United will attempt to put some pressure on Arsenal, who next play at Bolton on Monday, by beating Ipswich at Portman Road on Saturday evening.

Victory over George Burley's side would take United to within two points of Arsenal, although they would have played a game more.

United must do without more than half of their first team at Ipswich as Laurent Blanc, Juan Sebastian Veron and Fabien Barthez have joined David Beckham, Gary Neville and Ronny Johnsen on the injured list.

In the Frenchman's absence, Ferguson will play the relatively inexperienced duo of Wes Brown and John O'Shea at centre-half.

Fabien Barthez has a rib injury and Roy Carroll will deputise for him in goal, while Veron has suffered a recurrence of his Achilles trouble.

One plus for United is the return to fitness of skipper Roy Keane and the Irishman will start his first game since April 2.

Victory for United could mean relegation for Ipswich - if Sunderland win at Charlton earlier in the day - after two eventful years back in the Premiership and Ferguson feels sorry for Burley.

'I feel for George Burley and he's done a great job down there with the injuries he's had this year,' he said.

'It was an amazing season they had last year and they were at the top of the league for most of the season.

'That was a truly remarkable season for them in their first year back in the Premier League. I really think injuries have cost them this year.