Labour leader Ed Miliband has insisted he is focused on winning an outright majority for his party, despite contacts with senior Liberal Democrats raising the prospect of a centre-left coalition after the 2015 contest.
Mr Miliband said reports of discussions with leading Lib Dems such as Business Secretary Vince Cable were "overdone".
In an effort to distance himself from the junior coalition partner, he insisted they were an "accomplice" to the Tories in Government and were heading in the wrong direction.
Asked about the messages from Mr Cable on BBC1's Andrew Marr Show, Mr Miliband joked: "I've actually changed my mobile phone, I thought I needed to get away from him."
But he added that the pair had "talked about a whole range of issues" that were "private, mostly" but included a briefing on what the Vickers commission on banking's report would say.
But he dismissed any talk of overtures from the Lib Dems about a possible tie-up in the event of a hung parliament in 2015.
"This is way overdone. I want a majority Labour government, I'm working for a majority Labour government," he said.
"If there are areas where people can co-operate across the divide in politics, fine."
In an attack on Nick Clegg's party he said: "The problem about the Lib Dems, including Vince I'm afraid, is that they are an accomplice to this Government, not a brake on it.
"When it comes to the economic plans that are not working, the NHS plans that are wrong, what's happened on tuition fees, they are going in the wrong direction."