Norman Lamb has said he wants to build a progressive movement to take on the Tories as Labour moderate MP Liz Kendall heads to the Liberal Democrat party conference to join his call for a cross-party commission to address the NHS crisis.

Suffolk Conservative MP Dan Poulter – a former health minister – has also put his name to a statement which warns England faces a serious existential challenge, with partisan politicians failing to come up with a long-term solution.

Mr Lamb, the MP for North Norfolk and a former health minister, said it was important for the Liberal Democrats to show that they were not tribal, and to work with other progressives. But said his party had to be careful about how it collaborated.

'I don't have anything in common with Jeremy Corbyn, but I have a lot in common with loads of Labour people. We have to be quite careful. It can't be a marriage of convenience. It has got to be based on principle about things you believe in so you can have some coherence to what you are arguing for.'

Liberal Democrat leader Tim Farron clashed with predecessors Nick Clegg and Lord Ashdown over the weekend about whether the party needed to form electoral pacts with others to take on the Tories.

Mr Farron pointedly dismissed such talk as a 'parlour' discussion of no interest to voters after Mr Clegg suggested a realignment of the centre-left, and Lord Ashdown called for a single pro-EU candidate to fight the Tories in the looming Witney by-election caused by David Cameron standing down as an MP.

Mr Lamb said: 'I don't know how things will develop between now and 2020, but I think all the people who feel it is important in this country that there should be a real choice between the Conservatives and an alternative, that we work towards a progressive force that could win in 2020 and at the moment we are a million miles away from that.'

He said it was critical for democracy that there was competition. Following the resignation of Mr Clegg as leader of the party last year, Mr Lamb stood for the Liberal Democrat leadership, losing to Mr Farron.

He was given a standing ovation after his speech on health and social care on Saturday in which he announced he was setting up a panel to look at how a separate tax to pay for health and social care could be introduced, and how much it would need to raise.

He cited examples of constituents, telling activists that the personal stories were 'deeply distressing'.

'The man who came to see me on my village tour whose wife had been stuck in hospital for four weeks after being declared ready for discharge because they had been unable to sort out a care package;

'A nine year old constiutent whose parents were told they would have to wait nearly three years for a diagnosis of possible autism – a waiting time repeated all over the country.'

Dr Poulter said: 'With waiting times increasing, and older and more frail patients trapped in hospital because of a lack of available community support and social care, our NHS and care system is struggling to maintain high standards of patient care under current funding plans.

Given the additional pressures of an ageing population, increasing patient demand, and an urgent need to increase the availability of mental health services, it is essential that we agree a sensible way forward that provides our NHS and care system with the sustainable funding settlement that it needs to continue to provide high quality patient care.'

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