Harry Patch, World War One veteran, died on 25 July aged 111
The Royal British Legion in Somerset says it is appalled that a tribute to Harry Patch has been posted on the British National Party website.
Robin White, chairman of the Wells branch, believes the tribute implies that the BNP stands for the same things Harry Patch stood for.
"Knowing Harry as I did, he would have no truck with the BNP," he said.
A spokesman for the BNP criticised the Royal British Legion for making the matter a political issue.
"I think it's a shame that these organisations are coming out to have a pop at the BNP when we've always supported the troops," said John Walker.
Mr Patch, the last surviving tommy from the trenches of World War One, died last month at the age of 111.
"Harry's whole ethos was about peace and reconciliation," added Mr White.
"My understanding of what the BNP does is in no way related to peace and reconciliation."
It is not the first time that the Royal British Legion have been critical of the BNP.
In May, they wrote a private letter to BNP leader, Nick Griffin, asking him not to wear a poppy badge.
They accused Mr Griffin of trying to politicise "one of the nation's most treasured and beloved symbols".