OK. Research done.
The Committee has 9 members, and the Tories have 5 members, so a majority. Labour have 2 members, SNP, and a Former Sea Lord (presumably Independent).
In an effort to engineer a Conservative majority on the committee, the government removed Robin Janvrin, a crossbench peer, from the committee, to enable Graylings coronation.
Grayling has a long list of embarrassing failures on his CV (remember him awarding an £80million ferry contract to a company who had never run a ferry service).
The Committee were so horrified at the prospect of Grayling getting the Chair, that they told Lewis he would win if he stood. Lewis took the bait and Grayling was dumped.
Basically the Government were amateurish and out manoeuvred, Boris has a huge majority, but has acted very peevishly at not getting his way.
Lewis is essentially a Tory euro sceptic and he and Boris should be natural bedfellows. But Grayling is more toadying and Boris wanted to reward him.
Lewis won the contest and is now leader of this very influential committee. He does like to rebel, so maybe he will flourish in his forced independent status.