Sinn Féin has rejected the idea there can be a time limit on the Brexit backstop.
It comes as political parties are still struggling to find an answer on how to protect the EU single market while also avoiding customs checks on the border.
The backstop has been the sticking point in negotiations between the UK and EU.
But Sinn Féin's Eoin Ó Broin has rejected the idea that it can be made time limited in order to secure a deal .
"Would you trust Boris Johnson with a time-limited backstop?" asked Mr Ó Brion. "I don't think any sensible Irish person would.
"Previous agreement on the backstop provides for that.
"What we want is the absolute minimum level of disruption, whether it's on the border or at points of entry, and that means the single market and the customs union."