Plans for the Northern Forest, which will stretch from Humberside to Merseyside, were announced last year.
Now Huddersfield MP Barry Sheerman says the forested area should be broadened across the entire country as a tribute to those who fought and died for our freedom.
Mr Sheerman, who has been Labour MP for the town for 40 years, spoke in Parliament as the world marked the 75th anniversary of the D-Day landings on Thursday.
He said MPs should "think profoundly" about the young men and women who fought and lost their lives in the Second World War.
"There is going to be a new Northern Forest stretching all the way from Hull to Liverpool, 50 million trees.
"Could we expand that across the United Kingdom as a real tribute to those people who fought for us in the war, many of whom died fighting for the freedom of this country?"
Commons Leader Mel Stride replied: "We should seek whatever means we can to pay tribute to those who fought on our behalf in the Second World War.
"You have referenced the planting of trees and I remember, as a young boy actually, Plant A Tree In '73, I think is what we were urged to do way back then.
"I assume there are forests of these giant trees here today as a consequence of that particular initiative.
"You referred to the great Northern Forest, which I think is an excellent and an imaginative approach."
Mr Stride advised Mr Sheerman to bring the matter up at environment questions, which he said would be an "excellent opportunity" to suggest the idea to ministers.