Dozens of eurosceptic lawmakers from Prime Minister David Cameron's Conservative Party urged him to continue to lead the country whatever the result of Thursday's referendum on Britain's EU membership.
Robert Syms, a Conservative member of parliament for Poole in south-western England, said he delivered a letter to Cameron's secretary on behalf of 84 Conservative supporters of Vote Leave as voting closed at 10 pm (2100 GMT) Thursday.
The letter thanked Cameron, who campaigned for a Remain vote, for "giving the British people a choice of their destiny today," Syms wrote on Twitter.
"We believe whatever the British people decide you have both a mandate and a duty to continue leading the nation implementing our policies," the letter said.
The signatories included senior Conservatives Boris Johnson and Michael Gove, who led the Vote Leave campaign but are long-term political allies of Cameron.
Syms said many other Vote Leave supporters had "expressed their support" for Cameron but were unable to sign the letter, which carried handwritten signatures.
Before the poll, Cameron promised to continue to serve as prime minister until the end of his term in 2020, even if he lost the referendum.