Renegotiating the UK’s relationship with the European Union, earlier this week, grandees of European and British politics spent the day simulating renegotiation talks during a ‘mocked up’ summit.

The simulation also explored what negotiations might look like if Britain voted to leave the European Union.

John Bruton, Taoiseach of Ireland 1996-1997, said the consequences for Ireland would be serious: “Ireland regarded Britain’s exit as an unfriendly act. Peace in Ireland would be set back considerably if, as a result of the UK leaving, the EU we had to re-introduce border posts along the line of Ireland to collect tariffs on EU exports to the UK and vice versa and also had to prevent EU immigrants entering Britain.

“We’d have to have border controls and the effect this would have on the people of Northern Ireland and on the atmosphere of peace we’ve created through years and years of and hard work would be very very bad indeed.”

Another politician to raise concern was the former Italian Prime Minister, Enrico Letta, also a participant. He warned: “If such an exit occurred the consequences would be very negative and as a result of such irrational actions years and years of negotiations [would be needed to resolve it].”

He pointed out that it would pose a big problem for the competitiveness of both the UK and Europe because it would spend and waste a lot of time and money just for the legacy of the Brexit.

Meanwhile, others hinted there may be little good-will towards the UK if it voted to leave the European Union- meaning the likelihood of arranging a suitable trade deal between the EU and the UK would be made difficult. There were also warnings that many of the freedoms the UK expected to achieve if it voted to leave the EU would turn out to be a mirage.

Participants warned that agreements such as those on free trade, the movement of workers and the conduct of UK financial services would still be subject to either direct or indirect EU influence.

During the round table discussions, British politicians were warned “there is no such thing as a free lunch”. In other words it would not be able to cherry pick its best deals. It also warned that British citizens inside the EU would be at a serious disadvantage with “questionable legal status”.

Moving on to a discussion about London continuing as Europe’s financial centre, there was broad agreement that continuing to have a financial centre outside of the European border was not viable, as the former EU trade commissioner Karel de Gucht pointed out: “How can you expect after leaving the European economy that that economy would accept its financial centre is outside its borders?”

Although this was a simulation the politicians agreed the scenarios and discussions were realistic with former politicians ploughing through possible scenarios, seeking to find a solution.

This was an interesting exercise which gave observers, and other interested parties, an opportunity not just to see what could happen in the specific scenario of the UK voting to leave the European Union but also it provided refreshing insight into how serious political negotiation takes place and how politicians resolve issues through, often heated, discussion and compromise.