The Daily Mail reported the exit polls showed Brown's party could sustain its worst defeat in 79 years, though it appeared neither Labor nor the Conservative Party would win enough seats to nail down a majority in Parliament on their own.
The British newspaper said its Labor sources indicated Brown would resort to offering Liberal Democrats a referendum on voting reform in return for their support to keep his coalition government going. But Liberal Democrat leader Nick Clegg has previously hinted Brown would have to go as part of any deal. Foreign Secretary David Miliband is a possible successor, the newspaper said.
Home Secretary Alan Johnson said Brown should be given time to make a decision.
"Gordon deserves the dignity to look at these things and make up his own mind," Johnson said.
Other officials said Brown had the constitutional right to try to re-establish a governing coalition.
Conservative Party leaders said they believed No. 10 Downing was tantalizingly close as the British parliamentary elections played out.
A Times of London poll released Thursday backed up their confidence, indicating the Tories would make huge gains.
In a final push for votes Wednesday, Conservative leader David Cameron told supporters at a rally in Bristol not to "let fear triumph over hope. A Conservative government can get our economy moving again, can tackle our social problems, can make politics accountable."
In Dumfries, Scotland, Brown had urged voters to vote for the Labor Party "at this moment of risk to our economy, at the moment of decision for our country."
Clegg told a crowd at Sheffield City Hall to "aim higher, don't settle for second best."