Martin McGuinness looks likely to make an historic trip to Windsor Castle to attend a State dinner being hosted by the Queen.
It is understood the Deputy First Minister will be on the guest list for the formal dinner in honour of Irish President Michael D Higgins. Mr Higgins will stay at Windsor Castle during his four-day State visit to Britain next month, it has been confirmed.
The itinerary of the trip, the first such visit by an Irish head of state to the UK, includes a banquet, a speech at the Palace of Westminster, and a lunch with Prime Minister David Cameron at Downing Street.
On Tuesday, April 8, a full State banquet will be held at Windsor. The Irish and British Governments have declined to comment on the guest list, but it is expected that First Minister Peter Robinson and Mr McGuinness will be invited. Two days later Mr Higgins will attend a "Northern Ireland-themed" reception at Windsor.
While Mr McGuinness and the Queen have already met and shaken hands, the visit would mark an historic visit by a senior Sinn Fein member to a royal residence.
Invites have not yet gone out but when Mr McGuinness, a former IRA commander, receives one as expected, a decision on whether to attend will have to be taken by the Sinn Fein ard chomhairle.
Neither Sinn Fein nor the Government would comment on whether he will attend but as Mr McGuinness has already met the Queen, in the Lyric Theatre in Belfast during her Golden Jubilee year, it is thought there will be no obstacle in his way.
The decision to invite President Higgins to stay Windsor Castle, seen as the Queen's home as opposed to Buckingham Palace, is being seen as a sign of the close relationship between the UK and Ireland. The visit comes three years after the Queen's successful State visit to Ireland in 2011.
Speaking to the Belfast Telegraph, Ireland's Ambassador to the UK Dan Mulhall said: "This is the two heads of state coming together – they have met before of course, the last time was in Belfast in 2012. It is a very significant moment. It continues that onward and positive journey on which we have been engaged now for quite a few years and I hope that people in Northern Ireland will see this visit as a very positive development and something they can all, whichever tradition they come from, recognise its significance."
President Higgins and his wife Sabina will arrive in London on Monday, April 7. Anglo-Irish relations took a momentous step forward in June 2012 when Mr McGuinness, a former IRA commander, shook hands with the Queen at the Lyric Theatre during a visit to Belfast.