By Paul Reynolds BBC News Online correspondent

Winston Churchill warned General Bernard Montgomery soon after D-Day that he had to "inflict upon you a visit from General de Gaulle tomorrow".

The secret telegram is one of hundreds released in files of Churchill's wartime correspondence by the Public Record Office.

Most of them have been seen by historians - but they are now on open shelves for the public.

The telegram to Monty, encoded by a one-time pad - the safest method since the key is used only once and the message is too short to be broken - is typical of the Churchillian style and demonstrates how touchy his relationship with de Gaulle was.

Churchill tells Monty the de Gaulle visit must "on no account be a burden to you".

General de Gaulle received a "lukewarm" reception

Montgomery after all was fighting World War II.

"If such formalities exist in the battle area," the prime minister continues, "a guard may be found for him."

But he warns against letting the general grab the media, which were based near the Chateau at Bayeux that Monty was using for his headquarters.

The BBC studio incidentally is still there, in the turret of a castle next door.

"It will be much better he shall make any discourse he wishes after he returns to England," Churchill says.

Royal visit

"It would be undesirable to gather large crowds in Bayeux."

Churchill mentions a "personage" will also pay Monty a visit shortly.

This personage "should not be advised to go into danger".

A second telegram reveals it is the King.

Montgomery reports back on the de Gaulle visit.

In the event, it seems to have gone well.

"I paraded some soldiers and he made a short speech", Monty reported.

"The visit was a great success."

So de Gaulle had after all managed to say something.

And perhaps Monty suspected he was being a bit too upbeat.

He throws something Churchill's way, remarking the reception for de Gaulle in Bayeux had been "definitely lukewarm and there was no real enthusiasm".

During King George VI's visit, Montgomery was promoted to Field Marshall.