The UK Parliament voted to send its Prime Minister Theresa May back to the negotiation table with the European Union over their “divorce” plan known as Brexit. The Parliament also passed a (non-legally binding) resolution refusing to accept a “no-deal” exit from the Union.

The European Union, however, says that no renegotiation is possible. They say the agreement is the agreement and it can either be accepted by Parliament or not. Originally, the PM was expected to negotiate on behalf of her government mostly by herself, but this angered Parliament. An insurrection of sorts broke out and May was forced to put the agreement up for a vote. Had they accepted May’s negotiations, the issue would be over.

The main sticking point in the negotiations at this point is regarding the “Northern Ireland backstop.” The original agreement had allowed for temporary access to Northern Ireland from the Republic of Ireland (which is still in the EU) without the customs and immigration checks normally required at a country’s border. The idea was to continue negotiations on that particular point after the rest of the divorce had taken place.

The fear is that Northern Ireland could serve as a back door to the UK and that treating Northern Ireland as a special case within the UK could even end up breaking up the Kingdom altogether. Elements within Ireland have agitated for reunification for decades and could use this ambiguity to make that push again.

After Parliament’s vote, the EU continued to state emphatically that no new negotiations will be occurring. If they don’t cave on that, the most likely outcome would be a “no-deal” exit, a potentially catastrophic outcome with consequences that are not fully understood.

Some observers have stated that by voting against the Brexit deal negotiated with the EU while also voting to refuse a no-deal exit, Parliament has backed May into a corner with no exit. It may in fact in practice be impossible.