The only two parties in favour are Ap (labour party) and Høyre (conservatives) and in the latter there was substantial dissent. It only went through in the first place because the conservative leadership used the party whip in parliament.
Even though they still have a majority in parliament together, the conservatives are strengthened, and labour weakened, and a large part of the argumentation was that the EU "required" it. With this legal opinion I'd imagine at least some people in the labour party will consider opposing it, and more people in the conservative party - it's quite possible they'll find it hard to muster a majority to defend a challenge against the law.
Even though they still have a majority in parliament together, the conservatives are strengthened, and labour weakened, and a large part of the argumentation was that the EU "required" it. With this legal opinion I'd imagine at least some people in the labour party will consider opposing it, and more people in the conservative party - it's quite possible they'll find it hard to muster a majority to defend a challenge against the law.