Donald Trump has clear lead over rivals in final poll before Iowa caucus

The same poll also gave Hillary Clinton a slight lead over Bernie Sanders

(Getty)

Hillary Clinton is holding onto a slim lead over Bernie Sanders in Iowa as the nation prepares for Monday’s caucuses, according to a highly respected poll. The poll also gave a clear lead to Republican Donald Trump.

The poll by Bloomberg News and the Des Moines Register put Ms Clinton ahead of Mr Sanders by 45 per cent to 42 per cent. Former Maryland Governor Martin O’Malley was on three per cent in the survey conducted January 26-29.

Meanwhile, Saturday evening’s poll found Mr Trump leading Senator Ted Cruz 28 per cent to 23 per cent among likely GOP caucus-goers.

Hillary Clinton again faces an unexpectedly tough fight for the Democratic nomination (AP)

The poll, conducted by veteran pollster J Ann Selzer, also found Senator Marco Rubio with 15 per cent and retired neurosurgeon Ben Carson at 10 per cent

The poll is considered by pundits to be one of the most accurate, based on its performance in recent years and the woman who runs the poll, Ms Selzer, has an impressive track record.

Ms Selzer and her Des Moines-based firm, Selzer & Company, have polled for the Des Moines Register for decades and she was the only pollster to correctly predict the order of Democratic candidates in 2004.

The Politico website said that her final poll before the 2008 caucuses accurately predicted that a surge of first-time caucus-goers would help push Barack Obama to victory.

She also said former senator Rick Santorum’s surge in the waning days before the 2012 Republican caucuses when few others did. Just last year, she pointed to an Iowa Senate race that gave Republican Joni Ernst a seven point lead, contrary to other polls. Mr Ernst won by nine points.

“I think it has to do with being more of a traditionalist, science-based pollster,” she told the news website, explaining her remarkable accuracy.

“And because it has worked for me, I’ve not been tempted to go and try other methods. And because I have clients who are willing to pay the premium that it takes to do it this way, I’ve not had to cut corners.”