Also, it's only 2/3rds for a motion for an Early Election.
A motion of "No Confidence in the Government" only needs a simple majority and would result in an early election automatically if there wasn't a countering motion of Confidence within 2 weeks of the NC motion.
They can only do that if 2/3 of the HoC votes for it. This changed with the FTPA.
The opposition are unlikely to vote for it if it's going to allow the Tories to move from minority to majority.
The opposition may go for it if they think it's another bad call and they can inflict further damage on the Tories...