Labour’s latest big-name backing will force Tories to sit up and take notice

Editorial: With the support of the agency that helped deliver Thatcher to No 10, it is now up to the Labour leader to show that he can carry both the public and his party with him on the road to Downing Street

Advertising agency Saatchi & Saatchi has backed Keir Starmer to win the next general election (PA)

Ahead of any general election, there are barometer moments – the kind that make the major parties sit up and take notice.

For Labour, there has been a slew of by-election wins in recent months – the latest registering big voter swings in Mid Bedfordshire and Tamworth last month. The Conservatives clung on to Boris Johnson’s old seat of Uxbridge and South Ruislip by fewer than 500 votes in July, and lost Somerton and Frome to the Liberal Democrats in the same month.

National opinion polls have also been consistently against the Conservatives this year, with the latest Survation poll – based on new constituency boundaries that will take effect at the next election – suggesting that Sir Keir Starmer and his party would win a majority of more than 200 seats if an election were held tomorrow. That would be an even bigger landslide than Tony Blair pulled off.