FORMER US VICE president Mike Pence is to announce his campaign for president, setting up a challenge to his former boss, Donald Trump.

Only two years ago, their time in the White House ended with an insurrection at the US Capitol and Pence fleeing for his life.

Pence, the nation’s 48th vice president, will formally launch his bid for the Republican nomination with a video and kick-off event in Des Moines, Iowa, tomorrow, which is his 64th birthday, according to people familiar with his plans.

While Trump is currently leading the early fight for the nomination, with Florida governor Ron DeSantis polling consistently in second, Pence’s supporters see a lane for a reliable conservative who espouses many of the previous administration’s policies but without the constant tumult.

While he frequently lauds the accomplishments of the “Trump-Pence administration,” a Pence nomination in many ways would be a return to positions long associated with the Republican establishment but abandoned as Trump reshaped the party in his image.

Pence has warned against the growing populist tide in the party, and advisers see him as the only traditional, Ronald Reagan-style conservative in the race.

A staunch opponent of abortion rights, Pence supports a national ban on the procedure and has campaigned against transgender-affirming policies in schools.

He has argued that changes to social security and medicare, like raising the age for qualification, should be on the table to keep the programs solvent – which both Trump and DeSantis have opposed – and criticised DeSantis for his escalating feud with Disney.

He also has said the US should offer more support to Ukraine against Russian aggression, while admonishing “Putin apologists” in the party unwilling to stand up to the Russian leader.

Pence, who describes himself as “a Christian, a conservative and a Republican, in that order”, has spent months laying the groundwork for an expected run, holding events in early voting states like Iowa, South Carolina and New Hampshire, visiting churches, delivering policy speeches and courting donors.