A union boss has accused Tory Grant Shapps of "lying" about striking NHS ambulance workers.
Sharon Graham, General Secretary of the Unite union, told the BBC the suggestion made by Mr Shapps this morning that ambulance workers did not provide minimum service during strike days was "an absolute, utter lie."
Tens of thousands of nurses and ambulance staff in England are set to walk out on Monday in what is expected to be the biggest strike in NHS history.
The nurses are due to strike again on Tuesday while ambulance crews and call handlers will return to the picket lines on Friday.
It came after the Business Secretary accused ambulance staff of putting lives at risk by "refusing" to provide information on where they are striking, creating a "postcode lottery" for people having heart attacks.
Ms Graham said that's not true.
"I haven't used this word so much about politicians in the last 30 years, but he's actually lying," she told the BBC's Laura Kuenssberg.
"The idea that he's saying that ambulance workers did not do minimum cover in the dispute is an absolute, utter lie.
"It's important that we rectify that this morning. That is not true."
She went on to say Health Secretary Steve Barclay is "not telling the truth" in claims there is a dialogue between the government and unions over pay.
She added: "I can tell you categorically that there has been no conversations on pay whatsoever with Rishi Sunak or Steve Barclay about this dispute, in any way shape or form.
"They've danced around their handbag, they danced around the edges but they will not talk about pay.
"To me, that is an abdication of responsibility (as) the dispute is about pay - so how can they say they are in talks?"
Asked whether whether "on the eve of the biggest health strike in history there is zero conversation between anyone in your union and anyone at all speaking for the Government", Mss Graham replied: "I can absolutely categorically tell you that."
She went on: "I can categorically say to you we are in no talks at any level whatsoever with the Government about pay in the NHS, and that is a real abdication of responsibility.
"Why is Rishi Sunak not coming to the table? Instead of doing sort of press conferences about other things, come to the table and negotiate - roll your sleeves up and negotiate on the pay in the NHS, that is what's required."
She suggested the current state of the NHS, with people dying "just waiting for ambulances", means that "on a daily basis, this Government has put people's lives at risk".
On the need for talks, she said: "They need to come to the table. Where is Rishi Sunak?
"This is either because this man is out of his depth and he doesn't know what he is doing or there is a much more sinister reason for why they are doing this to the NHS."
Mr Shapps claimed: "We have seen the situation where the Royal College of Nursing very responsibly before the strikes told the NHS 'This is where we are going to be striking' and they are able to put the emergency cover in place.
"Unfortunately we have been seeing a situation with the ambulance unions where they refuse to provide that information. That leaves the Army, who are driving the back-ups here, in a very difficult position - a postcode lottery when it comes to having a heart attack or a stroke when there is a strike on.
"We cannot have that situation. That is why I am introducing laws for minimum safety levels."
Jonathan Reynolds, Labour's Shadow Business Secretary said he jokingly tells his children to behave as they "haven't got time to go to A&E under a Tory Government".
Asked if as a parent he worries about NHS strikes, Labour's shadow business secretary told Sky's Sophy Ridge On Sunday: "I think any family does, anyone in the country does.
"But I've got to say I feel worried now at the state of the NHS every day.
"Sometimes we'll joke to the kids 'you've got to behave, we haven't got time to go to A&E under a Tory Government', that's the kind of thing we'll say in our house because we know the pressures it's under.
"I don't think sometimes when the Government tries to cite the pressures of days when industrial action is taking place as the worry to families that they themselves are aware of just what kind of pressure and concerns there are out there every day because of the state of public services under their watch."
He suggested Labour in power would not be able to offer double-digit pay rises to public sector workers.
Asked if his party would give nurses a 10% pay rise, Mr Reynolds told Sky's Sophy Ridge On Sunday: "Realistically the top opening offer we probably wouldn't be able to meet that but we would negotiate.
"And fundamentally we have a much more compelling message about those workload problems because we've got that plan to abolish the non-dom rule for the super-rich and therefore use that revenue - over £3 billion - to vastly increase the numbers of doctors, nurses, midwives in the system.
"So that would be part of the negotiation."
