What is Horizon Europe and why has the UK rejoined?

It is the latest sign of improved relations between London and Brussels, though it came after prolonged talks across several months.

But why does the scheme matter and what does it mean for UK-EU co-operation?

– What is Horizon?

The scheme is a collaboration involving Europe’s leading research institutes and technology companies.

The latest iteration of the programme was initially launched in 2021 with a budget of 95.5 billion euro (£81.8 billion).

The scheme, which runs until 2027, is open to all types of organisations across Europe and the world.

Given the scale of the funding, it is a hugely important source of support for some of the world’s most important research projects.

– What is the link with Brexit?

Before the UK left the EU, the country was a member of Horizon. Ongoing membership or some form of future relationship was a key ask from scientists and universities during the protracted negotiations that followed the 2016 referendum.

Membership of the programme was eventually negotiated in the Brexit withdrawal agreement but the UK was frozen out of the scheme amid disputes between London and Brussels over the Northern Ireland Protocol.

– Why is there a deal now?

Tensions between the UK and the EU remained high during the premiership of Boris Johnson, amid anger in Brussels as the Government sought to backtrack on post-Brexit regulations for Northern Ireland and repeated threats to tear up the carefully negotiated deal for the region.

However, many Conservatives acknowledged the benefits of the Horizon scheme and it was hoped that a solution to the post-Brexit impasse in Northern Ireland could help forge a path for a UK return.

Rishi Sunak secured a long-awaited deal on the Northern Ireland Protocol in February in a major boost to relations with the EU.

Many expected that the Windsor Framework could mean a relatively swift UK return to Horizon. Now, seven months later, a deal has finally been agreed.

– Is there going to be UK-EU co-operation on other areas?

It is not just Horizon the UK is joining. The Government has also agreed to join the EU’s Copernicus space programme, although it will not take part in the bloc’s nuclear technology scheme Euratom.

There remain plenty of Eurosceptics on the Conservative backbenches and Mr Sunak – an original Brexiteer – is unlikely to want to do anything that would be seen as drawing the UK back into the EU’s orbit.

Nonetheless, he has shown a willingness to pursue better relations with the EU and the decision to join Horizon is unlikely to cause the Prime Minister much of a political headache.

Foreign Secretary James Cleverly, who took part in many of the talks that led to the breakthrough on Northern Ireland, said the move is what “effective engagement with Europe looks like”.

– How much does it cost?

Britain will contribute around £2.2 billion (almost 2.6 billion euros) per year to participate in both Horizon and the Copernicus space programme from January 1, when its association membership with the projects begins.

But the Government has been keen to stress that it represents good value for UK taxpayers.

The UK will not have to pay into the scheme for the two years it was frozen out, while the deal also includes a “clawback” mechanism that will allow the UK to be compensated if British scientists receive significantly less money than the UK puts into the programme.

– Who has welcomed it?

Scientists and university leaders have nearly unanimously praised the move.

Sir Adrian Smith, president of the Royal Society, said it is “fantastic news”, while Michelle Mitchell, chief executive of Cancer Research UK, said it will be “overwhelmingly in the best interests of cancer patients and scientists”.

Labour called the deal a “relief” but said it is “too late” for many researchers.