The Ministry of Defence has come under fire from MPs for buying early-warning radar aircraft for the RAF without an open competition.

The Defence select committee also attacked the Capita contract to recruit soldiers, which left the Army under-strength.

Appearing before the Defence Select Committee, Defence Secretary Gavin Williamson faced tough questions about the decision to hold talks with Boeing about a purchase of E-7 “Wedgetail” aircraft to replace Britain’s fleet of worn-out AWACS aircraft - also built by the US aerospace giant.

The committee heard how a rival offer to use Airbus jets equipped with radar from Saab was not fully considered for the £2bn-plus deal.

Mr Williamson said that the Wedgetail was already in service with Australia and buying it was “the most logical and cost-effective” option, with the “risk taken out of the programme” because it was already operational.