Stormont Deputy First Minister Martin McGuinness tonight called on First Minister Peter Robinson to publish his list of pre-conditions for devolving policing powers to Northern Ireland.

Amid a deepening rift between Sinn Fein and Democratic Unionists over the controversial move, the senior republican told the DUP leader he had to let people know exactly why he was still refusing to agree a date for the transfer of justice responsibilities from Westminster.

Sinn Fein has warned that any further delays will render the powersharing administration unsustainable - a claim that has been dismissed by the DUP as a bullying threat.

While both parties have agreed a £1 billion funding package with the British treasury, Mr Robinson is understood to have sent an eight page letter to Prime Minister Gordon Brown outlining a number of other so-called 'confidence building' measures his party want to see implemented before devolution takes place.

Among them are commitments to retain police officers currently employed in a reserve unit that is being axed and changes to how contentious parades in the region are managed.

But the DUP has denied this amounts to a shopping list of preconditions, insisting that the only precondition is the attainment of confidence within the unionist community for the move.

Tonight Mr McGuinness told an audience of republicans in Derry that the letter needed to be made public.

‘All of you are acutely aware of the difficulties we now face in relation to the transfer of Policing and Justice powers from London to here,’ he said.

‘Thirteen months ago Peter Robinson and I agreed a process which would see this happen and I quote 'without undue delay'.

‘The issue of funding was flagged up by both of us as vital to resolve. That, amongst quite a number of other matters, has been agreed.

‘Achieving community confidence was also an agreed part of the process. The people Sinn Fein represents have the confidence to support us in moving forward.

‘The DUP keep harping on about community confidence. Fair enough, but I must make it crystal clear that the eight page letter which I believe is loaded with preconditions and sent by Peter Robinson to the British Prime Minister, was neither seen or agreed by me, his partner in government, as part of our agreed process paper.

‘Therefore I believe that publication of this letter is both reasonable and essential.

The entire community is entitled to know what is in that letter. I am now calling on Peter Robinson to make the public aware of its contents. ‘

Mr McGuinness’ remarks came hours after Mr Robinson rejected Sinn Fein claims that he and his party were not governing on the basis of equality.

‘Simply because Sinn Fein has a demand and can't get other parties to agree with their demand isn't an example of inequality,’ he told the BBC.

‘It means that they haven't been able to pursue their political agenda or at least that aspect of it.

‘There's no requirement on me to meet the demands of Sinn Fein and to fulfil their political agenda.’

Although the row continues, Mr Robinson and Mr McGuinness last week sent out a joint letter to all Assembly members outlining the procedure for electing a future Justice Minister.

Both main parties have agreed not to nominate a candidate for the role, but have said the occupant must secure cross community support in a vote at the Assembly.

That marks out the non-aligned Alliance party as the clear favourite to take the portfolio.

But while the deadline for nominating candidates is next Friday, Alliance has indicated it will not do so until a policy programme for the Justice Ministry is set out.

Meanwhile, Alex Attwood of the nationalist SDLP said it would be unforgivable for the executive to fall over the issue of devolution.

‘The current DUP/Sinn Fein exchanges are all about the blame game,’ said the party's Policing Board representative.

‘The current exchanges throw a spotlight on how political power in the hands of the DUP and Sinn Fein comes back in the faces of the community.’