AL Carns, the former armed forced minister who left his role in protest earlier this week will join Laura Kuenssberg on the BBC's flagship Sunday political show as a panelist.
Carns quit on Thursday evening, writing to the Prime Minister to tell him he could not defend “a level of investment I know to be inadequate to the task”.
It came hours after defence secretary John Healey resigned, claiming Starmer had been “unable, and the Treasury has been unwilling” to provide adequate funding for the defence investment plan.
Also joining the panel will be crossbench peer Baroness Kidron, who has been a prominent supporter of the Online Safety Act and online regulation.
Broadcaster Richard Madeley, who previously hosted ITV's This Morning and continues to do so on an ad-hoc basis, will also be on the panel.
Being interviewed by Kuenssberg will be Culture Secretary Lisa Nandy, who has recently been seen campaigning alongside leadership hopeful Andy Burnham.
Following the resignation of two of Labour's defence representatives, the Conservative's shadow defence secretary James Cartlidge will be quizzed on the show.
Leader of the LibDems Ed Davey will also appear on the show.
Sunday with Laura Kuenssberg airs on BBC One and BBC iPlayer starting from 9am.