Last year, the group lost £34m and it is said to have a burn rate of around £1m a month and is only believed to have enough cash reserves to see it through next six months.
Its auditors Andersen Consulting raised eyebrows in April, during the group's full-year results, when it warned that the company required £46m in fresh funding.
The group has credit of £40m at Barclays, which is currently being renegotiated.
The Wireless Group's flagship brand TalkSport -- the former Talk Radio -- is struggling in the face of competition from BBC Radio 5 Live. In the most recent set of Rajar figures for the quarter to March 31, TalkSport netted 2.2m listeners against 5 Live's 5.7m-strong audience.
One problem TalkSport faces is that the Wireless Group, unlike the BBC, is not a member of the European Broadcast Union which distributes radio sports rights.
TalkSport has been unable to secure the rights to cover the forthcoming World Cup football qualifying match between England and Greece, which is being held in Athens. As a result, a reporter will provide commentary of the game from a hotel room in Athens, where he will be watching the match on TV.
MacKenzie has also been reported to be considering some unorthodox means of promoting his radio station, which could give it coverage on archrival Radio 5 Live.
The driver of the TalkSport-sponsored car in this year's BTCC Touring Car championship is said to be considering changing his name by deed poll from Nick Beaumont to Nick TalkSport. His team-mate in the B&Q TalkSport team has already changed his name to John B&Q after the DIY retailer which is co-sponsoring the car.
Such tricks hark back to MacKenzie's former home at the Sun newspaper, where the paper's national lottery correspondent changed his name to Lenny Lottery.
In another blow to TalkSport, the station has been reprimanded by the Radio Authority after a presenter called Liverpudlians "scumbags" on air.
The watchdog received four complaints about the outburst, which occurred during an on-air discussion about Liverpool in January.
The authority has also held up a complaint after a caller to the station swore on-air. The station apologised and said there had been a fault in the delay system, which screens out swearing.