The government is to set out details of its five-year defence strategy on Monday.

Speaking to the BBC's Andrew Marr on Sunday, Chancellor George Osborne confirmed that by 2023, the UK would have 24 F35 jets operating from its aircraft carriers.

A spokesman for the Ministry of Defence said those would be the first of a total order of 138 F35s - an expensive weapon, the helmets alone for which cost over £263,000 ($400,000).

Jonathan Beale tried the helmet for himself.