Michael Gove has said an anti-immigration poster produced by Nigel Farage made him "shudder".
George Osborne also this morning said the poster was "disgusting" and compared it to Nazi propaganda.
Last week Farage unveiled a pro-Brexit billboard that showed a queue of refugees and claimed the United Kingdom was at "breaking point".
Defending the poster, the Ukip leader said today it was no more "strong" than anti-EU posters created by the official Vote Leave campaign led by Gove.
And he said he did not think there would have been as a big a row over the poster had Labour MP Jo Cox not been killed.
Speaking to the Andrew Marr programme this morning, Gove distanced himself from Farage. "When I saw that poster, I shuddered. I thought it was the wrong thing to do," he said.
The two men both want the UK to leave the EU - but have disagreed on campaign tactics.
Asked about Gove's criticism, Farage told ITV's Peston on Sunday programme: "Have you seen their posters? They have been doing very strong posters, not only about Turkey but the number of terrorists and criminals that have come into Britain under free movement rules."
Farage later told Sky News the poster "reflects the truth of what’s going on".
"I wish an innocent MP had not been gunned down in the street," he said. "Frankly had that not happened I don’t think we would have had the kind of row over it."
The referendum campaign began again today, after being suspended on Thursday following the death of Cox.
Osborne, also launched an attack on the Ukip leader today and accused him of "whipping up division" and "making baseless assertions that millions of people are going to come into the country in the next couple of years from Turkey, or saying that dead bodies are going to wash up on the beaches of Kent"
"That disgusting and vile poster that Nigel Farage did which had echoes of literature used in the 1930s," the chancellor and 'Remain' campaigner told Marr.
"That is what we should say no to and this referendum vote is a vote on the kind of Britain we want."
Suggested For You
SUBSCRIBE AND FOLLOW
Get top stories and blog posts emailed to me each day. Newsletters may offer personalized content or advertisements.Learn more