THERESA May will today stress the need for the West to continue to uphold “our shared values and way of life” as she takes part in the official commemorations in Portsmouth of the 75th anniversary of the D-Day landings.

The Prime Minister will host 13 world leaders, including Donald Trump, the US President, Angela Merkel, the German Chancellor, Emmanuel Macron, the French President, and Justin Trudeau, the Canadian premier.

This is the first time the UK has hosted this many world leaders outside a formal summit since the 2012 Olympics.

Representatives from every country that fought alongside the UK in Operation Overlord – the Battle of Normandy – will attend commemorations alongside The Queen, the Prince of Wales, members of the armed forces, and more than 300 veterans, who are all over 90 years old.

As she prepared for the event, Mrs May underlined the importance of continued western unity, saying: “The Normandy landings 75 years ago were a moment of historic international co-operation.

“And it is right that at the heart of today’s commemorations are the veterans who fought to secure the liberty and the peace that we now enjoy.

“The global challenges we face today are different in their origin and nature but as we confront new and evolving threats to our security it is more important than ever that we continue to stand together in upholding our shared values and way of life.”

The PM insisted the bravery and sacrifice displayed on the beaches of Normandy by allied soldiers, which marked a turning point in WW2, would never be forgotten.

“Their solidarity and determination in the defence of our freedom remains a lesson to us all. And we will continue to stand up for the values of democracy, justice and tolerance that so many died to preserve.”

The event will involve an hour-long performance on Portsmouth’s Southsea Common, telling the story of the eve of the invasion of Normandy.

It will feature testimony from veterans, theatrical performances and live music, ending with a flypast of 24 aircraft, including the Red Arrows and Spitfires.

During the performance, Mrs May will read a letter from Captain Norman Skinner of the Royal Army Service Corps to his wife Gladys on June 3 1944. The letter was in his pocket when he landed on Sword Beach on 6 June. Capt Skinner was killed the following day, leaving his wife and two young daughters.