Former European Commission President Jacques Delors, often regarded as the mastermind behind the contemporary European Union, has passed away at the age of 98, as announced by his daughter.

Recognized for his pivotal role in establishing the single market, facilitating the unrestricted movement of people, goods, and services within the EU, Delors served from 1985 to 1995.

Additionally, he laid the foundation for the euro, the single European currency.

Despite his contributions, Delors faced criticism, particularly in the UK, where he was viewed as a symbol of interference from Brussels.

The Sun, a British tabloid, famously declared, "Up Yours, Delors." Delors' daughter, Martine Aubry, revealed that he peacefully passed away in his Paris residence on Wednesday morning.

French President Emmanuel Macron commended Delors as a "statesman with a French destiny" and an "inexhaustible craftsman of our Europe," expressing sorrow and acknowledging his enduring influence.

Delors, who also served as the French finance minister from 1981 to 1984, received accolades for his three-term tenure as the European Commission president, making him the longest-serving individual in that role.

Current European Commission President Ursula von der Leyen described him as a "visionary who made our Europe stronger," while European Council President Charles Michel hailed him as a "great Frenchman and a great European," underscoring his lasting impact on European history.

A French Socialist, he was a firm believer in post-war integration.

As well as the single market and the euro, his tenure at the top of the EU saw the creation of the Schengen agreement for travel and the Erasmus programme for student exchanges.

But for the UK's ruling Conservative Party under Margaret Thatcher, moves towards a federal Europe were seen as anathema.

Thatcher described the 1989 Delors report calling for economic and monetary union as unacceptable, because it would wrest many economic policies from the hands of the British Parliament.

Lord Clarke of Nottingham, who as Kenneth Clarke served in Thatcher's cabinet, told BBC Radio 4's PM programme she shared Delors' vision of a single market, but suspected him of also wanting a political union, which she was against.

"The truth was that Jacques Delors and Margaret Thatcher deeply disliked each other personally, they hated each other for personal and political reasons," he added.

Former UK opposition leader Neil Kinnock told the programme he was a "very polite, calm, highly intelligent man, a problem-solver" and not a "fanatical federalist" as Thatcher tried to portray him.

On leaving his post in 1995, Delors declined to stand for the French presidency, despite a huge lead in the polls.

He remained true to his federalist ideals. More recently, he warned of the dangers of populism in Europe, calling for bold moves in the wake of Brexit.