Wilfred Frost and John Healey went head-to-head on Sky News.Sky News presenter Wilfred Frost clashed with a cabinet minister over the government’s latest defence spending pledge.He told defence secretary John Healey that the promise was “entirely uncredible” unless he explained how it would be paid for.Nato leaders will agree at a summit in The Hague later today that all of its member states will commit to spending 5% on defence and national security by 2035.That will be made up of 3.5% on core defence spending, with the remainder in other security areas.It comes after Keir Starmer announced earlier this year that the proportion of gross domestic product (GDP) the UK spends on defence will rise from 2.3% now to 2.5% by 2027.Frost told Healey: “With all due respect, defence secretary, we’re at 2.3, and you’ve outlined how by this parliament you’ll get to 2.5. It is entirely mea