LONDON (Reuters) - Fifty-four percent of Britons would vote to remain in the European Union while 46 percent would opt to leave, according to an ICM telephone poll for the Guardian newspaper published on Monday.
The poll, carried on the Guardian's website, excluded those who do not know how they will vote in the June 23 referendum.
A parallel online poll by ICM showed "In" and "Out" voters tied on 50 percent each. Previous comparative figures were not immediately available.
The Guardian quoted John Curtice, a professor of politics at the University of Strathclyde as saying: "Whereas Internet polls have for months been suggesting a country that is split down the middle, until recently this was offset by the surveys done over the phone, which were recording a far higher share for Remain, sometimes approaching 60 percent."
Curtice noted that in the last few telephone polls, this proportion had dipped below 55 percent.
(Writing by Stephen Addison; editing by William Schomberg)