Chris Huhne's ministerial career appears on the line as pressure grows over his speeding points scandal.
The latest revelations from two Sunday newspapers draw further attention to claims that Mr Huhne asked someone else to accept speeding points on their driving licence on his behalf.
Both the Sunday Times and Mail on Sunday newspapers printed quotes from a recording of a phone call which took place before the allegations were first published last week.
'All of our customers are international and we need those transport links to be as efficient and effective as possible'
'Because key gateways have been capacity constrained, a lot of freighter services now terminate in mainland Europe'
They quoted the Liberal Democrat energy and climate change secretary reiterating his denials of any wrongdoing and asking the person involved not to talk to the press.
"There's no question of it coming out, because it's simply not true, that's it," Mr Huhne says in the recording.
The other person responds by saying: "I'm sorry, what? Why are you suddenly saying that?"
Mr Huhne is heard urging the other person not to let "the genie" out of the bottle and adds: "There is no evidence for this story unless you give it some legs by saying something. The last thing you want is a half-baked story saying you've taken points for me."
The allegations originally surfaced after his ex-wife, Vicky Pryce, claimed that Mr Huhne had persuaded someone to accept penalty points. He left the well-respected economist for his former spin doctor Catrina Trimingham last year.
Ms Pryce said that "he does drive a bit like a maniac" and claimed he "pressurised people to take his driving licence penalty points".
The alleged incident is thought to have occurred in 2003, when Mr Huhne was a member of the European parliament.
In one extract from the transcript of the recorded phone conversation published by the Mail on Sunday, the person Mr Huhne is talking to says: "I just cannot lie. It's one of the things that always worried me when you made me take them in the first instance."
The energy secretary replies: "I really don't think it is sensible to have these sorts of conversations on the phone. I'm very happy to meet and talk if you want to."
Mr Huhne, who was among the most critical of the Conservatives for their conduct in the alternative vote referendum campaign, is thought to be deeply ambitious. He lost the party's 2007 leadership election to Nick Clegg.