Sheikh Jassim bin Hamad Al-Thani is set to up his Manchester United bid to £5.5billion - in a bid to blow rival Sir Jim Ratcliffe out of the race.
United owners the Glazers have set a deadline of 9pm on Wednesday for prospective new owners to submit revised bids for the world's biggest football club.
Initial bids from Qatari banker Sheikh Jassim and INEOS owner Sir Jim Ratcliffe came in around the £4.5bilion mark – well short of the £6bn wanted by the Glazers.
While Ratcliffe is also understood to have increased his bid for United, he is not thought to have gone as high as £5.5bn, which could see the Qataris secure the sale.
Once the revised bids are submitted by interested parties, a preferred bidder will be identified by Raine, the US investment bank conducting the sale on behalf of the Glazers.
The chosen candidate will then be given further access to more club documents, in order to carry out full due diligence ahead of a proposed agreed sale with United's current owners.
Representatives of Sheikh Jassim visited Old Trafford and United's training ground last Thursday, while Sir Jim Ratcliffe and his team made the same visit the following day.
Both parties held positive meetings with United officials, including chief executive Richard Arnold, and are committed to a takeover, with the Qatari bid the current favourite.
Ratcliffe indicated his unwillingness to pay over the odds for United in an interview with the Wall Street Journal when he said: "What you don't want to do is pay stupid prices for things because then you regret it subsequently.”
In the same interview, Ratcliffe also said his interest in buying United was "purely in winning things" and called the club "a community asset", rather than a financial one.
The Qataris have proposed a 100 percent buyout of United and have pledged to clear historic debt heaped on the club by the controversial leveraged purchase by the Glazers in 2005.
In contrast, Ratcliffe has signalled his intention to acquire a majority stake by buying out the shareholding of the Glazers, which currently stands at 69 per cent.
Critics of the Qatari bid say it amounts to an attempted state takeover, similar to those at Manchester City, Paris St Germain and Newcastle, with Sheikh Jassim a member of the country's ruling family and son of the former Prime Minister.
The charge levelled at the Qatari bid is that its main objective is 'sportswashing' - buying United as a way of bolstering its global image and distracting from the country's oppressive human rights record and discriminatory laws.
