Defence Secretary John Healey sparked frustration on BBC Breakfast this morning as he repeatedly refused to explain how he plans on funding a promised defence spend increase.
Mr Healey was accused of "gambling" his hopes on economic growth, which as of yet has not materialised.
Yesterday the Government published its major Strategic Defence Review, setting out the threats facing Britain and what is needed to protect the country from enemies like Russia and China.
Part of the review demanded an increase in defence spending from the current 2% to 3%, while Keir Starmer has only committed to 2.5% by 2027.
The top Labour minister was ambushed by the blunt question: "How are you going to pay for this?"
Mr Healey merely explained how the Government plans on funding its 2.5% commitment with a £5 billion spending increase in defence, rather than addressing the 3% requirement.
Host Sally Nugent called the minister out on this, hitting back: "So that's to get to 2.5%. Beyond that, how are you going to pay for it?"
"Because we have discussed with you on this programme before the percentage needs to go up."
Mr Healey repeated his point about how the Government is set to reach 2.5% of GDP on defence, sparking Ms Nugent to once again interrupt.
She said: "Forgive me. I don't quite understand this. You're not saying how all of that is going to be paid for beyond 2.5%."
Mr Healey responded: "Well, we've said how we'll pay for the 2.5%."
"We will never make commitments to increase funding unless we can show how we're paying for them, and we're switching money out of overseas development aid in this parliament to be able to increase this defence spending, a record increase - a level this country has not spent since 2010."
Ms Nugent eventually got the Defence Secretary to admit he is relying on Rachel Reeves' promised economic growth to fund the spending uplift.
He revealed: "Well, in the end everything about a country and what it aims to do depends on economic growth, and that's why it's the number one mission of this government.
"It's why my job as defence secretary is to make defence investment, this record investment, an engine for growth in this country; more British jobs, better British businesses, greater innovation, greater right across the UK, we will do that, and we're doing that."
However he was accused of "gambling on growth" in order to meet the required defence spend, which is already less than the 3.5% of GDP many NATO allies are demanding as quickly as possible.
Last night two former Conservative Defence Secretaries warned that Labour's "breezy sloganeering" is not enough to keep Britain safe.
Ben Wallace and Grant Shapps warned: "It's simple: invest now and buy peace, or fumble down the back of the sofa when the storm has already broken."
"And until that choice is made - properly, publicly, and with conviction - the only thing 'ten times more lethal' in this review is the gap between the rhetoric and the reality."
