The upcoming junior doctors' strike "risks the safety of many patients", the Health Secretary has claimed as the Government and medics again lock horns over the proposed new contract.
Jeremy Hunt also urged the British Medical Association (BMA) to call off the strike and meet him, but refused to delay the introduction of the new contract as had been suggested in a last-minute cross-party proposal over the weekend.
In response, the BMA rejected Mr Hunt's claims that the principal outstanding issue in the contract negotiation is Saturday pay, and again offered to call off the strike if he agreed to lift the threat of imposing the contract while talks resumed.
On Saturday, a rainbow coalition of MPs including Labour shadow health secretary Heidi Alexander urged Mr Hunt to test the contested new work contract in a small number of trusts rather than impose it across England without the support of the BMA.
However, the Health Secretary insisted that the Government was already planning to roll out the contract slowly and dismissed the proposal as Labour "opportunism".
Instead he wrote to the BMA chairman, suggesting that they meet to discuss other issues affecting doctors such as improvements in training saying :"Next week's withdrawal of emergency care by junior doctors, called by the BMA, seriously risks the safety of many patients who depend on the NHS."
In the letter to Mark Porter, Mr Hunt added: "The extreme action planned will be deeply worrying for patients and place enormous additional strain on our NHS at a time of intense pressure.
"I therefore appeal to you one final time to call off strike action that will see doctors withdraw potentially life-saving care, and to meet with me on Monday to discuss a better way forward."
Mr Porter responded on Sunday, explaining the BMA's objections and calling on the Health Secretary to remove the threat of contract imposition as a settlement "cannot take place with the threat of imposition hanging over our junior doctors' heads".
He said: "For the sake of clarity, we must, once again, reject your assertion that the only outstanding issue in dispute relates to Saturday pay.
"Your own letter recognises a number of critical issues concerning work-life balance, excessive working hours, improvements in training and crucially, workforce and funding implications for seven day services.
"The proposed contract is deficient in failing to address these issues properly, hence our concerns for patient care, the long-term future of the NHS and the recruitment and retention of doctors."
Ms Alexander, Conservative Dr Dan Poulter, Lib Dem Norman Lamb and the SNP's Dr Philippa Whitford said in a letter to Mr Hunt that they wanted an independent evaluation of the so-called "weekend effect" which sees higher mortality rates for patients admitted at weekends as well as a scheme to introduce the contract as a pilot.
The two-day all-out strike is set to start on Tuesday at 8am and the NHS has already cancelled 125,000 operations and appointments in preparation.