British Prime Minister Theresa May's Brexit deal came under fire from ministers in the House of Commons on Wednesday.
The government was forced to publish the full legal advice it was given over Brexit after MPs found ministers in contempt of parliament for only giving a summary.
The advice warned that a hard Irish border could last "indefinitely", which would mean the UK could be locked in “protracted and repeated rounds of negotiations” with the EU for years to come.
The Northern Irish Democratic Unionist Party, which is in coalition with May's government said the legal advice about the deal was “devastating”.
Nigel Dodds, the deputy leader of the DUP warned the legal advice proved that Northern Ireland would be subject to different EU regulatory and customs rules to the rest of the UK.
Meanwhile, the DUP's Gregory Campbell said the advice says "the backstop will endure indefinitely". He asked May why the UK has allowed the EU to use this as a negotiating ploy.
May said there would be various ways out of the backstop and there is a commitment to avoiding a hard border in Ireland.
"We will negotiate as the UK," May added.
Security and immigration in life after the EU
The theme of the second day of the Prime Minister's five-day debate was security and immigration
Home Secretary Sajid Javid said he agreed with May's deal in saying it will have a "significant impact" on both topics.
Javid said security arrangements would be different under the deal but argued May's Brexit plan was "the most comprehensive agreement the EU has with any third country."
Adding that: "No one can pretend this deal is perfect in every sense. Inevitably there will be some compromises with this deal."
The Home Secretary said the big issue for the Home Office is immigration. "People voted to have control over it in this country," he said and argued that this is what the deal delivers.
"Free movement will end. The decision in the future will rest with the UK itself," he said.
He added that immigration has been good for Britain and it is why the government's first priority is to safeguard the position of EU citizens currently living in the UK, and those living in the bloc.
"EU citizens make a huge contribution to our economy, they are our friends, colleagues and neighbours, and we want them to stay," he said.