The SNP's Westminster leader Ian Blackford has accused the Prime Minister of having no alternative plan for Brexit.

Theresa May suffered a historic Commons defeat on Tuesday night as the withdrawal agreement she struck with the EU was rejected by 432 votes to 202.

The majority of 230 against marks the greatest parliamentary defeat of any sitting UK Government in history.

Speaking at Prime Minister's Questions on Wednesday, May told Blackford she would "listen to parliamentarians" to try to find a way forward.

The SNP MP urged the Prime Minister to legislate for a second Brexit referendum - branded by pro-Remain campaigners as a "People's Vote".

First, she faces a vote of no confidence in her government tabled by Labour leader Jeremy Corbyn, to be held on Wednesday evening.

Blackford said: "Yesterday, the attorney general said that any new deal would be much the same as the one already on the table.

"We know that the European Union won't renegotiate.

"If the Prime Minister survives today to bring forward her plan B, will she concede that plan B will basically be a redressing of plan A?"

May answered: "What we want to do following the defeat that we had in this House last night is listen to parliamentarians and find out the point at which, what is it that would secure the support of this House?

"That is the question that we will be asking. But that is against the background of ensuring that we deliver on the referendum result.

"That we leave the European Union and we recognise what people were voting for when they voted in that referendum result.

"An end to free movement, ensuring that we can have our own trade policy with the rest of the world, be fairer to our farmers, fairer to our fishermen, but maintain that good relationship with our neighbours in the EU."

Blackford accused the Prime Minister of failing to answer the question and said she had "failed".

He continued: "What an omnishambles from this government, suffering a historic and a humiliating defeat - the worst for any UK Government.

"Westminster is in chaos, but in Scotland we stand united.

"Scotland voted overwhelmingly to remain and we will not allow our country to be dragged out of the European Union or brought down by this Tory government."

Blackford said May "must now seek the confidence of the people, not just this House, extend Article 50 and ask the people if they want the Prime Minister's deal or remain in the EU".

The Prime Minister hit back: "This House legislated for a people's vote, it legislated for a people's vote that was held in 2016, and that vote determined the UK should leave the European Union.

"He talks about our country. Our country is the whole of the United Kingdom - England, Scotland, Wales and Northern Ireland.

"It is for the whole of the United Kingdom that we will be looking for a solution that secures the support of this House and ensures that this parliament delivers on the vote of the people."