However, the sources refused to disclose the contents of the message.
The protest to President Nixon is believed to have been sent through the U.S. Ambassador in Canberra (Mr. Walter Rice).
It follows the resumption of massive American bombing of North Vietnam this week when peace talks between the United States and North Vietnam reached a deadlock in Paris.
It is understood the Australian Government received no prior warning of the resumption of the bombing.
Mr. Whitlam told a press conference in Canberra on Tuesday that Australia did not expect to receive any communication from the U.S. on the bombing question, as our forces had been withdrawn.
Mr. Whitlam said he regretted that the ceasefire negotiations had broken down.
“Obviously, we hope that the negotiations are soon resumed,” he said.
Asked to comment on the resumption of the bombing, Mr. Whitlam said: “I don’t think a comment would help. We would like to have the negotiations resumed. That’s all I feel I should say.“
Observers were surprised that Mr. Whitlam did not take the opportunity, to condemn the resumption of bombing.
He has been a strong critic of the U.S. bombing policy in the past.
It appears that Mr. Whitlam refrained from making his views public on this occasion because of the firm, private protest he was sending to President Nixon.
The chairman of the Victorian A.L.P. (Mr. George Crawford) yesterday called on Melbourne workers to attend today’s demonstration against the war.
“I appeal to workers to knock off from their Christmas parties and demonstrate in the City Square against the U.S. bombing of North Vietnam,” he said.
The demonstration will be held in the City Square at 4 p.m. today and follows calls earlier this week from trade union officials and peace movement organisers for action to end the war.