A Tory MP has switched to the Remain camp in protest at Leave claims on the NHS.
Commons Health Select Committee chairwoman Sarah Wollaston hit out at the Brexit claim that withdrawal would hand the NHS an extra £350 million a week.
The Totnes MP said she was changing sides because she was not comfortable with the claim being on the side of the Brexit battle bus.
Wollaston wrote on her blog: "It's far easier as a politician to stick immovably to a declared position but more honest to set out why I will now be voting for Britain to remain a member of the EU.
"The claims about health from the leave campaign have been shameful. They have knowingly placed a financial lie at the heart of their campaign, even emblazoning it on their battle bus alongside the NHS branding to imply a financial bonanza. It's an empty promise and one which would soon backfire.
"A strong economy has always been the cornerstone of funding for the NHS and for all the arguments about the scale of the economic turbulence, the clear consensus is that the effects would be significant and negative."
"Listening to the evidence, the EU has played a positive role in promoting good health whether that be in terms of water and air quality or the scientific research for which the UK is clearly a net beneficiary. We contribute 11% of the EU research budget and receive 16% of its allocated funding."
She added: "The leave campaign has redrawn its battle lines around immigration for the final weeks of the campaign. It looks increasingly indistinguishable from UKIP but the immigration card may prove an empty promise if the price of trade with the EU requires the free movement of people. It will also have left a bitter legacy of division."