Former president George W Bush is to hit the campaign trail to boost younger brother Jeb’s faltering presidential nomination bid. The 43rd US President will appear at a rally in South Carolina on monday, ahead of Saturday’s primary election.

Mr. Bush’s legacy has come under fierce attack from Republican frontrunner Donald Trump in a televised debate. His brother, the former Florida Governor, has spent a lot of campaign cash but failed to make an impact.

He is struggling to catch up with Mr. Trump and Texas senator Ted Cruz, who won the New Hampshire and Iowa contests respectively. Mr. Bush’s famous family has largely kept out of his presidential nomination battle and he insisted last year that he was running as his own man.