Trump maintains huge Iowa polling lead as Nikki Haley gains ground

Major poll shows Trump 27 points ahead before first Republican primary vote but Haley climbs to 16% alongside Ron DeSantis

Donald Trump maintained his huge lead in the crucial early voting state of Iowa in a major new poll by NBC News and the Des Moines Register but Nikki Haley is now emerging as his closest challenger.

The former US president has a 27-point lead in Iowa three months before the first vote of the Republican primary as he attracted 43% support. But Haley, the former South Carolina governor and United Nations ambassador, climbed 10 points to 16%, sharing second place with Ron DeSantis, the Florida governor whose campaign has long been seen to be stalling.