Speaking during PMQs, the Labour leader demanded the prime minister call a general election immediately.
“Across our country the British people are rolling-up their selves and getting on with it,” Starmer said.
“Doing their best in a punishing cost of living crisis, and a government that has abandoned them.
“The truth is his candidate in Tamworth summed up perfectly how he and his Tories are treating the British public.
“Will he just call a general election and give the British public the chance to respond as they did in Selby, Mid Beds and Tamworth.
“They have heard the government telling them to ‘f-off’ and they want the chance to return the compliment.”
Andrew Cooper, the losing Tory candidate at last week’s Tamworth by-election, was revealed to have told parents who struggled to feed their children to “fuck off”.
Sunak refused to condemn the comment during last week’s PMQs, the day before the by-election which saw Labour overturn the huge Tory majority to snatch the seat.
Starmer’s call for a general election came as Sunak marked one year as prime minister.