On Monday, Speaker of the House of Commons John Bercow ruled that Prime Minister Theresa May cannot bring her Brexit deal back to Parliament for a third vote — at least in the deal's current form.

Considering that the European Union has ruled out renegotiating the terms of Brexit, Bercow's action creates a major obstacle. Up until now, May had hoped to bring her deal back for a third vote that might just have scraped over the line. But now, with Britain's March 29 deadline for leaving the EU rapidly approaching, one of two things seems likely to happen: Either Britain will leave the EU without a deal, at the risk of significant economic hardship, or the EU will accept Parliament's desire for an extension to the March 29 deadline.

While it is likely that the EU will grant an extension, Bercow's rebuke means that May is caught between that extension and no obvious means of getting a deal-based Brexit into effect. After all, if May cannot call a vote on her deal and the EU won't renegotiate it, what can she do?

That raises another question: What is Bercow's thought process?

I don't buy the speaker's claim that he was forced into this action by parliamentary conventions reaching back hundreds of years. I suspect that Bercow's ultimate motivation here is forcing May to call an election. Bercow is renowned for his interest in retaining public spotlight, and were he to force an election, he'd win a place as one of history's most powerful speakers.

In the short term, however, this is just another curve ball for Brexit.