A bid to block the Government's controversial health reforms has been launched in the House of Lords.
As peers began a marathon debate on the changes, spread over two days, Labour's Lord Rea urged them to refuse the Health and Social Care Bill a second reading.
The former GP took the unusual step of tabling the amendment because he claimed ministers had failed the coalition's pledge to stop "top-down" reorganisations of the NHS.
Lord Rea told a packed chamber the reforms were not either a manifesto commitment or in the coalition agreement.
"Instead of having a Bill that was in a manifesto, we have a Bill that was expressly ruled out by David Cameron and subsequently in the coalition agreement," he said.
But health minister Earl Howe defended the changes, insisting they would "liberate the NHS" and improve patient care in England. He denied they amounted to "top-down reorganisation", saying the reverse was true with innovation being "unleashed from the bottom-up" with clear lines of accountability.
Lord Rea's call came after more than 60 leading medical professionals called on ministers to scrap or substantially rewrite highly controversial NHS reforms.
On Sunday thousands of protesters against the changes, aimed at giving clinicians control of commissioning budgets and increasing competition, converged on Parliament, blocking Westminster Bridge for two hours.
Health Secretary Andrew Lansley has already been forced to amend the proposals after putting them on hold in the teeth of widespread opposition from health professionals earlier this year.
Around 100 peers have indicated they want to speak in the debate, which the Government has extended until Wednesday when the key votes will be taken.