The South Staffordshire MP admitted he has yet to have a formal meeting with the Chancellor over the UK's defence budget, but said he saw the current two per cent of GDP level of funding 'as a base, as against a ceiling'.

Mr Williamson, who was handed the key Cabinet position earlier this month, also told MPs that the RAF would continue to fly missions over Iraq and Syria 'for a good while more' to counter the threat of dispersed ISIS fighters.

An eventful session in the Commons saw Mr Williamson warned of a Tory rebellion unless defence budgets were bolstered; confirm the UK's commitment to NATO and Trident; and attack Jeremy Corbyn's Labour party for 'not believing' in the British Army.

He also announced that a rise in personnel was being sent to Afghanistan to support the indigenous army.

Speaking at defence questions, Mr Williamson described concerns over new defence cuts as 'a vary valuable point', and added: "I'm taking the opportunity to look at all the work that has been done and making my own judgement on this."

He said he had yet to meet Philip Hammond to discuss spending on the armed forces.

"What I want to do is to make sure that we have the arguments ready, understand the threats that this country faces and make sure that we deliver for our armed forces," Mr Williamson said.

"That is what the focus is going to be. I have many conversations with the Chancellor and I'm looking forward to many, many more going forward."

Responding to calls that he should demand three per cent of GDP be spent on defence 'to prevent the armed forces from being hollowed out', he said the current two per cent level should be seen 'as a base, as against a ceiling'.

Conservative James Gray warned him that if the government sought to use the National Security Capability Review 'as camouflage to cut services' he will 'face a very substantial rebellion'.

"The defence of our nation is the government's primary responsibility," Mr Williamson responded, adding that he will 'do everything he can to deliver' for the armed forces.

Questioned on the UK's support for the Afghan army, he announced there will be an uplift of 85 personnel to support its work, along with 60 further service personnel to continue that training.

Pressed by shadow defence secretary Nia Griffith to tell the Chancellor that 'enough is enough' on spending cuts, Mr Williamson said it was 'a little bit rich' for Labour to lecture the Tories on defence, particularly a party whose leader 'doesn't believe in the British Army' or Trident.

Steady start for 'charmed' Gavin

As despatch box debuts go, it was steady rather than spectacular.

But considering the background to Gavin Williamson's maiden Commons appearance as Defence Secretary, he will probably be quietly content that he survived it unscathed.

For a start, the South Staffordshire MP's rise to the lofty Cabinet position has been questioned by many, who say he is too green or take offence at his remarkable ability to ladder climb.

And his new brief is fraught with difficulties, with a Tory rebellion brewing if the government fails to come up with the money needed for the armed forces.

He may have thought life in the Whips office was tough, but this is a whole new game of soldiers.

A few eyebrows were raised when he admitted he had not yet spoken to the Chancellor over defence spending, arguing that he wanted to first 'understand the threats faced by the UK'.

While that claim is likely to have convinced nobody, he was more persuasive when dealing with a warning about the prospect of a backbench uprising over defence cuts.

In response he insisted two per cent spending on defence was the bottom rung, said the world was becoming more dangerous, and described concerns over budgets as 'very valuable'.

His underlying message to the Treasury was clearly 'show me the money'.

With the Government on the ropes and crying out for some steely determination, this was no time for a Cabinet Minister to be going on the back foot.

And as Mr Williamson showed repeatedly during his time as Chief Whip, his default position is to come out swinging.

But he will need to adopt a measured approach at the Ministry of Defence, and his attack on Labour's defence record came over as rather trite, as John McDonnell might say.

There was a moment of mirth among the serious debate, with his old foe John Bercow announcing his surprise at the Defence Secretary's 'charm' at the despatch box.

It was rather fitting, as many would observe Mr Williamson has led a charmed life in politics up to now.