The French opposition is grilling President Emmanuel Macron for his refusal to invite Russian President Vladimir Putin to a D-Day ceremony in Normandy marking 75 years since the Western Allies invasion and liberation of Nazi-occupied France.

Earlier in June, Kremlin spokesman Dmitry Peskov officially confirmed to reporters that Moscow had not received an invitation from Paris to attend the celebrations. Russian Foreign Minister Sergei Lavrov later said that the country would only be represented by a diplomat from its Paris Embassy.

However, Macron invited his other cunterparts — the president's closest allies — from across the globe. He received US President Donald Trump, outgoing UK Prime Minister Theresa May and over a dozen other world leaders in Normandy to commemorate the historic event.

D-Day, or the Normandy landings on 6 June 1944, was the largest seaborne invasion in history, carried out by the Western Allies during World War II, it marked the beginning of the liberation of German-occupied France and the opening of the second front.

During previous D-Day ceremonies, world leaders hailed the significant Soviet contribution to the victory over Nazi Germany. The Soviet Union paid the highest price for the defeat of fascism — an estimated 26 million Soviet citizens died during World War II, hundreds of cities were destroyed, and infrastructure in areas was destroyed beyond repair.

The USSR was the key player on the Eastern Front and, according to many historians, Overlord Operation, also known as the Battle of Normandy, on 6 June 1944, could have failed.

The French opposition has criticised Macron’s decision, saying that the move is merely a humiliation of the nation that fought the Nazis alongside France.

"75 years ago, ‘the supreme battle’ was held on our beaches in Normandy. The gratitude of the French people to the Allies and Resistance fighters of the interior will remain eternal. As general De Gaulle said: 'Long live France, free, in honor and independence!'" Nicolas Dupont Aignan, president of the party Debout la France, said.

He insisted that the absence of an invitation for Putin was "inexplicable and humiliating to our Russian friends".

"How to explain such an absence, while the Soviet Union played a major role in the victory of the Allies? It is impossible to understand, except to consider that it is a political decision by President Macron", he said.

According to the politician, the move undertaken by the Macron administration is not in the interest of the country.

"This diplomatic blunder is absolutely not in the interest of France since Russia is turning more and more toward the East and China as the mistakes made by Europe accumulate", Dupont Aignan added.

National Rally leader Marine Le Pen also said that she regretted that Russia had not been invited to the D-Day commemorative ceremony in Normandy.

"Today we are honouring the memory of young soldiers who fell for our liberty 75 years ago, as well as those who were part of all the French Resistance [movements]. But it is regrettable that Russia is not taking part in the commemorations despite having paid a heavy price", she tweeted.