Mourinho, sacked by Chelsea in December, has been heavily linked with Van Gaal's job at Old Trafford.

United are currently one place outside the Premier League top four and were knocked out of the Champions League at the group stages.

There have been suggestions that should the Red Devils fail to qualify for Europe's elite club competition next season then Van Gaal will be axed.

Mourinho has publicly confirmed he wants a new job in time for next season and despite his agent Jorge Mendes holding numerous talks with United a concrete deal has yet to be offered.

And according to The Sun, a 'twitchy' Mourinho wants a written promise from the Manchester club that he will be their new boss this summer.

It is said there is a split at board level over his appointment - with United's owners the Glazer family and executive vice-chairman Ed Woodward keen but legendary former manager Sir Alex Ferguson and director Bobby Charlton unsure.

Ferguson backed Van Gaal to stay last week and the pressure has eased on him with successive 1-0 victories over Everton and Manchester City, as well as an FA Cup quarter-final replay at West Ham to come.

And the Daily Mirror report that Van Gaal believes he will remain as United manager for next season - even if they do NOT finish in the top four.

The 64-year-old thinks Ferguson's defence of him and his impressive blooding of numerous young players this season - particularly striker Marcus Rashford - could keep him in a job.

Reports in Holland claim Van Gaal has been given 'assurances' over his future and told of an £80m transfer pot for the summer, with £50m-rated Everton hitman Romelu Lukaku supposedly his top target.

Van Gaal is also said to have turned down a director position with the Netherlands FA.

United are next in action on Sunday (4pm) when they travel to White Hart Lane to take on title challengers Tottenham.