The T-shirts feature an image of the weapon and the slogan “Arm John McDonnell Now!” and were worn by activists at a Young Labour rally attended by Jeremy Corbyn last week.
Furthermore, the T-shirts display Labour’s red rose logo above the words “Labour Party Young Guerrillas”.
Last night, Tory MP Philip Davies said: “These T-shirts are tasteless and an insult to the memory of those killed by the IRA and are symbolic of what the Labour Party has become.
“It is no wonder their activists eulogise John McDonnell after his previous support for the IRA.”
However, a spokesman for John McDonnell said he had “nothing to do with these T-shirts” and that the item was also “nothing to do with the party”.
The spokesman said: “He does not approve of violence or glamorising it.”
The T-shirts were worn by activists at a Young Labour rally attended by Jeremy Corbyn
Labour's Annual Conference takes place every Autumn and is one of the largest and most high profile political events in Europe
The news comes after John McDonnell last week insisted there is “enough sensible people in the House of Commons” to stop Britain from leaving the European Union without a deal.
He said the Labour Party would be happy to “put aside party interests” to build a cross-party alliance to force the Government to “come to their senses” and only leave the EU with a deal.
Appearing on the BBC’s Andrew Marr programme, Mr McDonnell was asked how Labour would handle a no deal situation if they were to come to power.
John McDonnell: I still use Amazon but in a considered way.
The shadow chancellor replied: “I’m not willing to countenance that, I don’t think it is a realistic option.
“I don’t think there is a majority in Parliament for no deal.
“I think on a cross-party basis, you’ll see in the debates in the coming weeks, the Government will get the message – there will be a deal.”