New bid to reach Stormont deal
A serious effort is being made to address power-sharing difficulties at Stormont, Martin McGuinness said.
The parties are involved in political talks, convened by Northern Ireland Secretary Theresa Villiers, aimed at finding a new way forward on disputes causing logjams in the administration.
Historic probes into Troubles incidents have been hit by significant cuts to public finances, with the Police Service of Northern Ireland (PSNI), the Police Ombudsman and the Coroner's Service all facing resourcing challenges.
It follows disagreement over welfare reform and other budgetary issues as well as more long-standing differences over controversial parades, the legacy of the past and flags.
The deputy first minister said: "In the context of the present discussions it is fair to say that a very serious investigation is taking place as to how we can resolve the challenges to this administration as a result of policies being directed at us from London."
He said the block grant from Westminster which pays for public services had been "undermined" to the tune of more than £1 billion.
The Northern Ireland Secretary has said the Government would seriously consider any proposal from Stormont to fund a new mechanism to investigate the events of the Troubles.
Ms Villiers said she could not promise money would be forthcoming, due to constraints on public finances, but said any suggestion would be "looked at with care" by Prime Minister David Cameron and Chancellor George Osborne.
There have been growing calls for the Government to contribute to potential new structures to investigate Northern Ireland's toxic past and the treatment of victims of violence.
Ms Villiers has said it was also vital that the Executive implemented efficiency programmes within the public sector to free up more funds for priority issues.
The talks resume in Belfast on Wednesday and the Cabinet member said it was time for the parties to "buckle down" and strive for consensus.