Last year, the Greek government made the announcement  that they had approached UNESCO , about inviting the UK to enter into mediation over the issue of the Parthenon Sculptures. The Intergovernmental Committee for Promoting the Return of Cultural Property to its Country of Origin or its Restitution in Case of Illicit Appropriation  sets out a series of rules , that such mediation should follow, although the case of the Marbles would be the first time it had actually been implemented.
Many naysayers suggested that despite this new initiative by Greece, the British Government & British Museum would not consider entering into such a procedure, as there was nothing in the rules to compel them to do so and no time limit for them to reply to the request.
There was also the issue, that in all previous requests, the British Government pointed out that such requests were a matter to be dealt with by the trustees of the British Museum, whilst the trustees would point out that they would not be legally allowed to de-accession the sculptures, under the terms of the British Museum Act 1963 .
Now, in what many involved with the case have suggested is an unexpected move, the British Government have responded to Greece’s minister of culture, indicating that they are happy to enter into mediation immediately. Under the UNESCO rules, the mandated timescale for the process to be completed in is one year, meaning that the issue of the Marbles could be resolved by 1st April next year, if not before.
The issues of the Marbles being a matter for the British Museum to determine were also noted by the government in their initial response, where they explained that whilst this has been the case in the past, it is really more of a political shorthand for noting that they are uninterested in resolving the issue, noting that as the museum is largely funded by the government, they do in fact have the ability to exert a large level of control over it & would do their utmost to ensure that the Museum was fully represented during the negotiations and to enforce whatever actions were agreed to at the end of the process.
Department for Culture, Media & Sport 
Notice of intention to enter into mediation with an aim to swiftly resolve the Parthenon Marbles issue
April 01, 2014
The British Government would like to notify Greece that we have accepted their invitation to enter into mediation via UNESCO, over the issue of the Parthenon Marbles.
Previously issues have been raised over whether we had jurisdiction over the British Museum, and there are still many question marks over this. However, in the interests of progressing the resolution of this long standing embarrassment to the British people, we are jointly going to co-operate with the trustees.
We acknowledge that the issue of the Parthenon Sculptures are a unique case, and, as such we are happy to do whatever it might take to resolve the issue.
Further updates will be posted on our website in due course.
On behalf of the International Cultural Property Unit, Department of Culture, Media & Sport
British Museum 
British Museum agrees to Greek Mediation proposal
April 01, 2014
Following a request from the Department of Culture Media & Sport, the British Museum has agreed to work in partnership with the government to satisfy Greece’s requests for mediation over the Parthenon Marbles issue.
This is not a decision that we were able to take lightly, but we realise it was a move that we had to make. We have gradually come to understand that issues such as this are not going to go away, and accept that we need to make more effort to try & resolve them, in the interests of maintaining the current levels of co-operation with countries such as Greece.
Various surveys have shown that our continuing retention of the sculptures is out of sync with public opinion. For a long time, the trustees hoped that this was a one off blip in the statistics, but we are now resigned to the fact that our continued retention of the sculptures is hurting our public image as world class museum.
We with Greece the best of luck with the mediation, and over the next year, will be able to tell you more, as the process unfolds.
Head of Press, British Museum