There is some sense left in the House of Commons:
Why? Let's play this out. There are just two choices available to us on Brexit if we are to leave. They are to stay in the single market, or not and to have free movement, or not. That's it. This then necessarily leaves four potential outcomes.
So we can stay in the single market and have free movement as option one. That is soft Brexit as the EU sees it. This is an available option. But hardline Tories say no.
Or we can have stay in the single market and have no free movement as option two. This is Boris Johnson's fantasy, but it is not and never will be on offer from the EU.
Options three is to be out of the single market but have free movement. No one, anywhere, is arguing for that.
Which leaves the only other viable option as alternative four, which is out of single market and no free movement. This is hard Brexit, of course.
This is the whole UK negotiating position summarised. There are massive complications arising from either of choices one or four which are the only two viable options, both of which are in my opinion still best avoided, but there are no more decision options on the table than that. And we don't even know which of those the UK is going for. The government has not said.
And because the government will not make clear its choice the only rational option available to any member of the House of Commons (and I mean any member) is to vote no to Article 50 right now. Until the option being pursued is clear then Caroline Lucas is absolutely right to be saying no to Article 50.