National Party MPs have been summoned for an "urgent in-person" caucus meeting in Wellington.

The National Party has been gripped by another round of discontent and speculation.

Christopher Luxon's grip on his leadership is again being questioned following a week of communication gaffes and a fresh report his MPs are unhappy.

NZ Herald's Katie Bradford says if Luxon is getting rolled, 'it needs to be this week'.

OPINION: The PM has called a caucus meeting to discuss his leadership on Wednesday.