Health minister Norman Lamb has called for cross-party talks to discuss the long-term future of the NHS.

Mr Lamb said the financial pressures on the NHS meant a “national conversation” was needed about how it could be sustainable over the coming years.

He told a fringe event at the Liberal Democrat party conference that the government was already committed to £20bn of efficiency savings over the course of this Parliament but a similar amount would be needed beyond 2015.

Mr Lamb said he “bears the scars” of cross-party talks before the last election on social care which ended in bitter division when the Tories launched their “death tax” campaign against Labour.

But he insisted fresh talks involving Labour and the Tories would be needed to examine the challenges now facing the health service.

He said the £20bn of savings under the “Nicholson challenge” set by NHS chief executive Sir David Nicholson were the start of an ongoing process.

“The idea of it was because health costs in every developed country are rising by about 4 per cent a year and no party has the money at present to throw in extra resources to cover that possible growth, you have to find efficiency savings to keep the system sustainable,” he said.

“But of course in the next Parliament you have to find another £20bn, or whatever it is, to keep the system sustainable.

“So this imposes an extraordinary pressure on the system and I think we need a sensible national debate, a national conversation. I would like all parties to commit to a discussion about how we ensure the NHS is sustainable.”