Jeremy Corbyn needs to "spell out" his commitment to protecting Northern Ireland after Brexit, SDLP MLA Claire Hanna has said.
Mrs Hanna, who is her party's spokesperson on Brexit, was speaking after Jeremy Corbyn instructed his MPs to vote against an amendment in the House of Commons which would have ensured the UK remained aligned with the EU's single market.
On Tuesday the Labour leader instructed his MPs to vote against a Norway-style option included in a Lords amendment to the EU withdrawal bill, which would retain membership of the European Economic Area (EEA) as an option.
It was reported Mr Corbyn rejected the option on the basis it would leave Britain as a rule-taker, without the ability to shape EU policy.
South Belfast MLA Claire Hanna said: "Jeremy Corbyn needs to spell out once and for all if he is committed to protecting Northern Ireland from Brexit because actions speak louder than words.
"As each day passes, and more revelations about the adverse impacts of Brexit comes to the fore, it becomes starkly clear that all of us across these islands must remain within the single market and customs union to prevent a catastrophic exit that will have an economically destabilising impact on businesses, trade and commerce, north, south, east and west."
Mrs Hanna added it was time for Mr Corbyn to "stop simply identifying the problem and start forming the solution".
Despite the date for Britain leaving the European Union being less than a year away, the form which post-Brexit customs arrangement will take remains unclear.
Speaking at the weekend, Irish Foreign Minister Simon Coveney rejected the possibility of any physical infrastructure on the island of Ireland.