THERESA May’s grand pledge that the age of austerity is over will be a “great big Conservative con” if she fails to boost public sector spending in the Autumn Budget, Jeremy Corbyn has declared.

The Labour leader eschewed the subject of Brexit and concentrated his fire at PMQs on austerity, pressing the Prime Minister on how she planned to end the funding squeeze on the police, the NHS, schools, councils and disabled people following her unexpected party conference vow.

But Mrs May hit back, claiming Labour's plans would cost people £1 trillion and, after all the country’s hard work, thrust it back to square one.

She repeated her pledge to end austerity and told MPs: "What is not being brought to an end is fiscal responsibility."

During sharp exchanges and after the PM raised her Government’s actions on tackling the issue of mental health, Mr Corbyn pointed to cuts to mental health budgets, the police and other areas as he asked when would austerity finally be over.

"Today there are 5,000 fewer mental health nurses than there were in 2010. The Prime Minister said last week that austerity is over. When will austerity be over for the mental health services?"

Mrs May insisted her Government was putting "record levels of funding into mental health", adding: "If he's saying to me that we still need to do more in mental health, I say yes, we do.

"That's exactly why we're setting out further steps today to improve the mental health of children and young people."

After defending the Government's record further, the PM in response to later questions said: "I've been very clear that there are better times ahead for people, we will see debt falling and we will see support for our public services going up.

"Austerity is being brought to an end. What is not being brought to an end is fiscal responsibility."

But Mr Corbyn hit out at "eight years of painful austerity" noting how poverty was up, living standards were down and public services were slashed while the super-rich enjoyed tax giveaways.

"The Prime Minister declared she is ending austerity. But unless the Budget halts the cuts, increases funding to public services, gives our public servants a decent pay rise, then isn't the claim that austerity is over simply a great big Conservative con?" he asked.

But Mrs May insisted wages were increasing and the minimum wage had risen. Income tax had been cut, fuel duty frozen and the energy price cap had helped working people.

"We know what would really hurt working people. Labour's plans would cost £1tr of people's money. Uncontrolled borrowing, spiralling taxes, working people paying the price of Labour; yet again, Labour taking us back to square one."