Short All In BET

[BROOKS]

Blinds are 200/400

Player in the BB is all in for 300
We know that it is still 400 to call, and if UTG wants to raise, they must raise to at least 800 (and that would be a raise of 400)

But what about a short all in bet...

On the flop, player bets all in for 300.
We know that UTG can call the 300, and if he wants to raise he needs to raise by at least 400 (because 300 isn't a legal/valid bet)
So UTG raises to 1000.
Is that a 700 raise or a 600 raise?
We need to know this, so we know what the next minimum to raise is.

[Steff0111]

It´s a raise of 700!