The billionaire, who also owns OK! magazine, is expected to be named today as the preferred buyer for the loss-making Five, after rival offers from Channel 4 and NBC Universal fell far short of his cash proposal, reports The Guardian.
"No-one else can get close to what Desmond is prepared to pay," said a source close to the sale negotiation process.
Desmond's deal is also likely to face limited regulatory issues as his share of the UK media market is relatively small and will not pose any major competition concerns.
However, Tory backbencher John Whittingdale, who chairs the Culture, Media and Sport committee, intends to ask Desmond to appear before members if the sale goes ahead.
Whittingdale and other MPs are concerned that Desmond could attempt to combat Five's low ratings by turning the channel into a 24-hour celebrity news and entertainment network, similar to E! Entertainment in the US.
Under Five's terrestrial licence, the commercial broadcaster must provide a set amount of news and current affairs programming every year.
Last week, Desmond met with media regulator Ofcom to give assurances that he will maintain the requirements of Five's licence, which runs until 2014.
Should the deal be confirmed, the media baron would be prevented from promoting his publications on the channel under EU cross-promotion rules.
However, he would be able to use his magazines and newspapers to promote Five shows to help boost the broadcaster's ratings share.
He could also look to use his existing commercial relationships with celebrities such as Kerry Katona and Katie Price, who are signed to OK!, to launch new shows on Five.