Four thousand UK passport-holders are trapped in the country, amid deadly fighting.
Labour's Rachel Reeves said: “All this Tory prime minister does is shrug his shoulders."
"This prime minister, who has been voted out by his party, having a jolly for six months is treating the British public with contempt, he should go now.”
A UK operation to evacuate British nationals and local Afghan allies is underway following Kabul's fall to the Taliban.
Summit follows jump in positive tests in the UK and Covid-19 spreading to Scotland.
Security services are already searching for another of the suspected killers, dubbed 'the man in white'.