The Northern Ireland Secretary has insisted that discussions around funding compensation payments to Troubles victims should not be holding up progress.
Brandon Lewis said victims have waited too long for the payments, adding the UK Government is “extremely disappointed by the current delay”.
Westminster and Stormont are at loggerheads over who pays the estimated £100 million cost.
The scheme which allows support payments, which range from £2,000 to £10,000 a year depending on the severity of the injury, was supposed to open to applications on May 29.
It is understood that Sinn Fein is declining to nominate a Stormont department to run the scheme because it objects to those with convictions of more than two-and-a-half years being excluded from applying.
Chair of the Northern Ireland Affairs Committee Simon Hoare wrote to Mr Lewis urging that a resolution be found to ensure compensation payments to victims and survivors can begin immediately.
In a responding letter, Mr Lewis said discussions about funding “are not preventing the Executive from being able to progress implementation”.
I must be clear that it is for the Executive to now put in place the arrangements that will allow victims to receive paymentsBrandon Lewis
“The key step to unblocking progress is the designation of a department to provide administrative support to the Victims Payments Board,” he said.
Earlier this week, Stormont Justice Minister Naomi Long indicated she is content for her department to administer the scheme.
Mr Lewis welcomed the move and said he “urges the Executive to formalise the way forward to get the scheme under way”.
“I have written and spoken to the first and deputy first ministers on several recent occasions about the need to address delay to the scheme,” he wrote.
“Sinn Fein has been clear that it wants to reopen the criteria by which eligibility for the scheme will be determined but this is already set in legislation and provides a fair basis for helping those who suffered most throughout the Troubles.
“It is therefore imperative that Sinn Fein, along with all the parties, enable the scheme to move forward as the time for delay is done.
“I will continue to urge the Executive to make progress and I will keep the committee updated on their progress.
“But I must be clear that it is for the Executive to now put in place the arrangements that will allow victims to receive payments.”
Sinn Fein’s stance has been criticised by unionist political parties.
Ulster Unionist MLA Doug Beattie said the party was “acting for the few, not the many”.
“The sheer audacity of Sinn Fein to want the UK Government to fund the whole scheme that covers many of the victims of the IRA who they supported is shameful,” he said.
“But to add insult to injury they want those IRA perpetrators to avail of the same payment to give them equivalence with their victims.
“This is Sinn Fein acting for the few, not the many, to preserve their own narrative of the past. They are abandoning hundreds of victims who had thought this issue had been resolved and it is totally unforgivable.”
TUV leader Jim Allister accused Sinn Fein of attempting to “rewrite the pension scheme to include their ‘heroes'”.
He has urged the UK Government to take control of the scheme.
“The only way forward now to thwart the Sinn Vein veto is for Westminster to take control of this pension and administer it across the UK,” he said.
“This is a key battle which Sinn Fein cannot be allowed to win. Innocent victims can take no more humiliation.”