By Andrew MacAskill
LONDON (Reuters) - Britain's next prime minister Liz Truss had a smaller margin of victory on Monday than any of her predecessors, suggesting she might have to work hard to heal a governing party deeply divided and lagging in opinion polls.
After a bitter contest, Truss won 57% of the votes from Conservative Party members compared to 43% for her rival, former finance minister Rishi Sunak, a margin that although comfortable was not as overwhelming as some polls suggested.
It was the narrowest victory since Conservative members were given a say on who to elect as their party leader in 2001 and she has a lower level of support among Conservative lawmakers than any of her predecessors this century.
Polls during the leadership campaign suggested that Truss's victory margin would be larger. A YouGov poll in August had Truss on 69% to Sunak's 31%.
"It was closer than expected," said Andrew Bridgen, a Conservative lawmaker. "By the end of the week, we'll get a new government and you'd be amazed at how this party can come together and unite."
In her acceptance speech, Truss ruled out a snap election and promised to deliver a "great victory" for the Conservative Party at the next general election in 2024.
"I campaigned as a Conservative and I will govern as a Conservative," Truss said. "We need to deliver over the next two years."
Scotland's leader Nicola Sturgeon, who wants her country to break away from the rest of the United Kingdom, and Frances O'Grady, the general secretary of the Trades Union Congress, mocked the size of the win.
Sturgeon pointed out that the size of Truss's victory was smaller than the support Scotland would need to win independence under a new law she is allegedly considering.
Truss is planning a new referendum bill that would mean Scotland could only win independence if 50% of those entitled to vote were in favour, not just a majority of those who voted, the Sunday Times reported.
O'Grady said the size of her win would not meet the threshold that Truss wants unions members to have to declare to for workers to legally strike in the future.
In 2019, Truss's predecessor Boris Johnson, who was forced to resign over a string of scandals, won 66% of the vote. In 2005, David Cameron's defeat of David Davis was even more commanding, with 68% of the vote.
The last three Tory leaders called on Monday for the party to unite behind Truss as the country's new prime minister, saying it was vital the Conservatives now work together to address the challenges facing Britain.
(Reporting by Andrew MacAskill, editing by Elizabeth Piper and Ed Osmond)