Sinn Féin will go to the House of Lords today to fight a British government decision to deny its MPs thousands of pounds because they refuse to take their seats in Parliament.
It is the latest stage in the bid by the party's four MPs to claim Policy Development Grants.
Efforts in the courts in Northern Ireland have failed.
The party have branded the refusal to give them the money an act of discrimination - made all the worse for them by the money being divided between MPs from other parties in Northern Ireland.
Speaking ahead of the hearing, Michelle Gildernew, the Sinn Fein MP for Fermanagh and South Tyrone, said: "The original decision to deny Sinn Fein Policy Development Grants in line with our mandate and representation was an act of political discrimination.
"The decision to allocate the monies due to Sinn Fein amongst our political opponents further exacerbated the situation."
She said that given the "political bias" and make up of the judiciary in Northern Ireland , the party had always believed they would have to go to the higher court to achieve a "just verdict".
