Republican presidential candidate Ted Cruz has received a boost from former contenders Scott Walker and Jeb Bush.

Scott Walker has halted his 2016 White House bid, warning the Republican race has become too nasty and calling on some of his party rivals to do the same, citing an urgent need to “clear the field” to help defeat front-runner Donald Trump.

Scott Walker has halted his 2016 White House bid, warning the Republican race has become too nasty.

Donald Trump will be there and, god only knows, what he will say - but there are nine other loose cannons onstage too.