Sinn Féin has said that some political parties at Westminster have made representations to it to take up its seats at Westminster.
The party's Deputy Leader Michelle O'Neill made the comments in London where she was part of a delegation of four of Northern Ireland's political parties to discuss Brexit.
Ms O'Neill said some Westminster parties had asked Sinn Féin to take up the seats it holds, but she said her party remained steadfast in the belief that a Northern Ireland backstop was the only viable option for Northern Ireland.
Sinn Féin has seven MP's elected to the House of Commons but they do not take their seats in Westminster.
Their abstention from the House of Commons is because the party refuses to recognise the legitimacy of British authority in Northern Ireland.
British Prime Minister Theresa May's government is currently sustained by the votes of the DUP.
Asked whether he believed Sinn Féin should be in Parliament voting on issues such as Brexit, the Liberal Democratic Party Leader Vince Cable said he understood the historic mandate of Sinn Féin, but it would be desirable that the party was represented fully in the House of Commons and he had raised this issue in an "amicable way".
The leaders of Sinn Féin, the SDLP, the Alliance Party and the Green Party all supported a Remain vote in the Brexit referendum.
They are in London for a series of meetings today including with the Labour leader Jeremy Corbyn.
SDLP Leader Colum Eastwood said it was important to remember that the four parties who visited Westminster today represent the majority view in Northern Ireland on Brexit.
This is a crucial week ahead he said adding that while Theresa May had refused to meet the group, it needed to be made clear to her that she cannot cast aside the agreements that have been made in the past in relation to Northern Ireland.
