UK foreign minister Liz Truss has joined the race to succeed Boris Johnson as prime minister and leader of the ruling Conservative Party, as the fractious contest focused on tax.

Truss, 46, announced her candidacy in The Daily Telegraph newspaper on Sunday evening, saying she had “a clear vision of where we need to be, and the experience and resolve to get us there”.

The bid by Truss, seen as a front runner in the Tory leadership contest, followed that of former defence minister Penny Mordaunt as the race expanded to 11 candidates.