This remarkable footage captures the day David Lloyd George cosied up to Hitler during a pre-war trip to Germany before hailing him as 'the greatest living German'.
The grainy black and white film shows the politician and his entourage travelling around Germany in 1936, where they dined with the NSDAP ruler and rode together on new autobahns.
The 16mm film also captures Lloyd George laughing with Adolf Hitler as he tours a Bavarian town.
In another clip, the British PM lays a wreath at a war memorial in Munich, while the flags of the NSDAP and the UK hang side by side in the background.
Following the visit, Lloyd George described Hitler as a 'remarkable personality' and lauded him as 'one of the greatest I have ever met in the whole of my life'. Hitler added that he was pleased to have met 'the man who won the war', prompting Lloyd George to call Hitler 'the greatest living German'. He said in a newspaper interview: 'Germany does not want war. Hitler does not want war. He is a most remarkable personality, one of the greatest I have ever met in the whole of my life, and I have met some very great men.
'Affection is a quite inadequate word to describe the attitude of the German people towards Hitler. It amounts almost to worship.'
He added that there was 'no whisper of criticism' of the german leader.
'I have never seen anything like it,' he continued. 'Some men I met who are not Nazis told me that they did not know what the country would have done without him.
'They are inclined to blame Hitler's supporters for some of the things which they do not approve, but there is no whisper of criticism of Hitler.
'It is just like our motto, "The King can do no wrong"'.
He also praised the National Socialist leader as 'the George Washington of Germany'.
The visit came about when Lloyd George, the Prime Minister during the First World War against Germany, visited Hitler's home at Haus Wachenfeld near Berchtesgaden in the Bavarian Alps.
The pair first met alone at the Berghof, before Lloyd George returned for tea the following night.
During the visit, Lloyd George was impressed by Germany's public works programmes which he saw first hand.
He believed Hitler was rearming Germany for defence and that a war between Germany and Russia would not happen for at least 10 years. The film, which belongs to a British historian, has now been put up for sale for £1,200. Ben Jones, auctioneer at Shropshire-based Mullock's Auctions which is selling the film, said: 'It is a significant film and interesting to see how Lloyd George was laughing and joking and everything appears to be okay.
'Hitler was able to cover up all of his emotions and what he was really thinking to fool people into thinking he was a different person to the one we witnessed by the end of the war. 'My guess is this film was made by someone from Lloyd George's entourage perhaps for propaganda purposes because you can see the Germans don't look at the camera while Lloyd George's entourage do acknowledge it. 'The person who has the film in his possession is a British historian who is a big collector with so much material he needs to start selling some of it.'