The Prime Minister has described the double Conservative by-election losses in Tamworth and Mid Bedfordshire as “disappointing” but said there were “local factors at play”.
Rivals Labour took both seats, which enjoyed healthy Tory majorities, in results that party leader Sir Keir Starmer said “made history”.
Both contests were triggered by the high-profile departures of their previous MPs.
Former cabinet minister Nadine Dorries quit – eventually – as Mid Bedfordshire’s MP in anger at being denied a peerage in former prime minister Boris Johnson’s resignation honours list.
Mid-term elections are always difficult for incumbent governments
In Tamworth, Chris Pincher resigned after being found to have drunkenly groped two men in an “egregious case of sexual misconduct” at London’s exclusive Carlton Club last year – an incident which helped trigger Mr Johnson’s exit from No 10 because of his handling of the situation.
Rishi Sunak, speaking to broadcasters as he prepared to fly to the UK from Egypt, said they were “obviously disappointing results” but that it was “important to remember the context”.
He said: “Mid-term elections are always difficult for incumbent governments.
“And of course there are also local factors at play here.”
The Prime Minister, who is returning after a diplomatic blitz of the Middle East, said he remained “committed to delivering on the priorities of the British people” following the defeats.
