Ted Cruz declared he would not release his delegates in at least three primary states, even though he is out of the race and the Republican convention is likely to nominate Donald Trump.

The Texas senator sent letters to state parties in Kansas, Oklahoma and Texas on Monday informing them he would keep the delegates he won during their primary contests. While in the race, Cruz won 546 pledged delegates. This move could lessen Trump’s delegate count and also give Cruz more direction over rules and procedures during the GOP convention.