US:Hillary Clinton has widened her lead over Barack Obama among Democrats and Rudy Giuliani has retained his over John McCain among Republicans, according to the first poll to be conducted since both parties held their first presidential debates.
The Gallup/ USA Todaypoll showed that, during the past three weeks, Mrs Clinton's support rose by seven points to 38 per cent, while Mr Obama's fell by three points to 23 per cent. Former vice-presidential candidate John Edwards saw his support drop from 16 per cent to 12 per cent.
Mr Giuliani has the support of 34 per cent of Republicans, compared to 20 per cent for Mr McCain, although other polls have suggested that the two men are running almost level.
The poll showed an enthusiasm within both parties for candidates who have not actually joined the race, with former vice-president Al Gore the choice of 14 per cent of Democrats, ahead of every candidate except Mrs Clinton and Mr Obama.
Among Republicans, former senator turned actor Fred Thompson is in third place at 13 per cent and former House speaker Newt Gingrich is in fourth place at 8 per cent.
Maryland governor Martin O'Malley will endorse Mrs Clinton today and New York governor Eliot Spitzer will follow suit next week.
Yesterday's poll shows President Bush's approval rating at just 34 per cent, the eighth consecutive month in which it has been below 40 per cent.
This is the longest stretch of such poor ratings for any modern president except Harry Truman during the Korean War and Richard Nixon during the Watergate scandal.
More than two out of three Americans disapprove of the way Mr Bush is handling the situation in Iraq and leading Republicans warned this week that their patience could fray if there is no improvement by September. Mr Bush last week vetoed a Bill that would have linked funding for the war to a timetable for withdrawing US combat troops.
Democrats will this week introduce a new Bill that would fund the war for a few months but would require Mr Bush to return to Congress in July to request further funding. The new Bill is unlikely to include a timetable for withdrawal but Democratic leaders are confident that it will win the support of most anti-war Democrats and could win over moderate Republicans.
Republican leaders condemned the plan to dribble out war funding in small increments in an effort to pressure the president into accepting a timetable for a withdrawal of US troops.
"Republicans will not support rationing funds for our troops in harm's way and neither will the American people. This is just the latest version of the 'slow-bleed' strategy Democrats began months ago to choke off funding for our men and women in uniform," said House Minority Leader John Boehner.
Meanwhile, the second-ranking Republican in the Senate said there must be "significant changes" in Iraq well before the end of the year, signaling President Bush could face new challenges on war policy from members of his own party.
Senator Trent Lott of Mississippi, who holds the second leadership position in his party, made his comments a day after similar remarks by Mr Boehner.
"I do think this fall we've got to see some significant changes in the situation on the ground, in Baghdad and other surrounding areas. . .or else," Mr Lott told reporters.
He would not elaborate on possible consequences.Gen David Petraeus, US commander in Iraq, is expected to deliver a progress report in September. - (Additional reporting Reuters)