Keir Starmer in diplomatic push to head off Middle East crisis ahead of G7 summit in Canada | Keir Starmer

Keir Starmer is beginning an urgent diplomatic push to try to head off the crisis in the Middle East, as the Foreign Office warned Britons not to travel to Israel after more retaliatory attacks by Iran.

Downing Street did not rule out the possibility of having to evacuate UK nationals from Israel if matters worsened further, saying officials were keeping all contingency plans “under constant review”.

The prime minister was to discuss the continuing clashes between Israel and Iran with the Canadian prime minister, Mark Carney, in Ottawa before heading to the G7 summit in Kananaskis, in the western province of Alberta.

While Starmer’s programme for meetings at the summit has yet to be set out, it is likely he will hold bilateral talks with leaders such as President Donald Trump,…