Russian mercenary boss Yevgeny Prigozhin told Defense Minister Sergei Shoigu in a letter published on Monday that the Ukrainian army was planning an imminent offensive aimed at cutting off his Wagner forces from the main body of Russian troops in eastern Ukraine.

In the letter published by his press service, Prigozhin said the “large-scale attack” was planned for late March or the start of April.

“I ask you to take all necessary measures to prevent the Wagner private military company being cut off from the main forces of the Russian army, which will lead to negative consequences for the special military operation,” he said, employing the term that Moscow uses for its war in Ukraine.

It was the first time Prigozhin has published such correspondence with the defense minister, whom he has frequently criticized over the conduct of the war.

The unusual move appeared to have two possible aims: to confuse Ukraine commanders and to seek to pin blame on Shoigu, not Prigozhin, if the purported Ukrainian manoeuvre proved successful.

Prigozhin said he was providing details of the Ukrainian plan and of his own proposal to counter it in an attachment to the letter, which he did not make public. He did not say how he knew of Ukraine’s intentions.

He said Wagner forces currently controlled 70 percent of the Ukrainian city of Bakhmut, which they have been trying to capture since last summer in the longest and bloodiest battle of the war.