Mike Pence shared a stern warning for his former boss on Sunday while promoting his latest book on America's major TV networks. 

In an interview with NBC's Meet the Press Moderator Kristen Welker, former Vice President Pence shared that the reason for his writing of the book was, 'because there's a new threat to that historic conservatism in the Republican Party ... from the populist right.'

Pence railed against the set of right-wing priorities which have found a foothold in the GOP in the Trump era, lamenting the embrace of policies such as 'broad-based tariffs, nationalization of businesses, [and] price controls.'

In a separate Sunday interview with Margaret Brennan on CBS' Face the Nation, Pence noted that In fact, Trump has 'said himself he's not a conservative, he's never really claimed to be.'

When asked about Trump's current Vice President, JD Vance, Pence noted that he is 'less clear' about Vance's views. 

'But I'm very clear, as I wrote in my book, that there is this new tension within the Republican party that will take those pieces of the agenda, the populist right agenda that President Trump has embraced, and try and make that the new direction of the Republican party,' Pence explained. 

'I think that'd be bad for the Republican party. I think it'd be worse for the country that needs a vigorous, strong conservative party committed to freedom, committed to free markets, committed to traditional values,' Pence added.

The former vice president also criticized the current Trump administration for not ending the nationwide access to the abortion pill which was made possible by the Biden administration. 

Abortion opponents have previously said they have no plans to let Trump avoid the issue for the remainder of his term. 

Marc Wheat, general counsel at former Pence´s political advocacy group Advancing American Freedom, has said that his group will increase pressure on the administration. 

Those efforts will include urging the FDA to speedily release documents about mifepristone that it owes the group through a lawsuit.

'President Trump thinks that pro-life is a loser,' Wheat said earlier this month. 

'He might see that the pro-lifers may not turn out in the numbers that he needs.'

Even as Trump and the Republican-led Congress face mounting pressure from the right to restrict access to medication abortion, Republicans around the country are far from united in taking that position.

Advancing American Freedom has grown significantly in recent months in part as conservative thinkers and scholars work to create a place to advocate for traditional conservative values in the Trump era.

Pence's feud with Trump started after the then-vice president voted to certify Trump's 2020 electoral loss on January 6th, 2021.

During his Sunday press rounds, Pence was also questioned on whether or not he would be supportive of Texas' GOP nominee for the US Senate seat Ken Paxton, who ousted incumbent Senator John Cornyn in a primary contest last week.

Pence stopped short of endorsing Paxton but stated that he could never back Democrat James Talarico 'who is a radical left,' and a major proponent of abortion,  before admitting that 'in many respects Republicans have lost our way. But Democrats have lost their mind.'

Pence also offered a bold midterm prediction, in which he sees Republicans keeping the US Senate in their control, as well as having 'a real shot to hold the House.'

Pence's book, What Conservatives Believe: Rediscovering the Conservative Conscience, is set to be released on Tuesday.