bar have been urged to immediately remove a drink named after Bloody Sunday.
The Sundae Bloody Sundae cocktail, available at the Adventure Bar in Covent Garden, is served with a toy soldier on top.
John Kelly, whose brother Michael (17) was among those shot dead in Derry on Bloody Sunday in 1972, branded the ice-cream drink "bloody well scandalous".
"I think it is completely disgraceful. It has upset and hurt the families," he said.
"I believe whoever thought this up should be ashamed of themselves.
"They are riding on the backs of innocent people shot dead on Bloody Sunday.
"They are forgetting that there are an awful of Irish people living in London too."
The name was criticised by Belfast man Adam McGibbon when he visited the London bar with friends on Monday.
Mr McGibbon said it was "grossly offensive".
"I think they should take the cocktail off the menu, admit that they made a mistake and that they were in-sensitive and just leave it at that," he said.
"They wouldn't have a cocktail for any other atroc ity that happened so why is there a Bloody Sunday cocktail?"
Staff at the Adventure Bar initially claimed the drink was a tribute to the Bloody Sunday dead although management later retracted this and claimed a social media intern had been trying to rectify the situation.
In a statement posted on the bar's website, it said the name was a reference to a scene about the U2 song Sunday Bloody Sunday in the Steve Coogan TV comedy series I'm Alan Partridge.
"It's easy to see how one or two ill-chosen quotes from an Alan Partridge episode can be taken so entirely out of context," the statement said.
SDLP assembly member Colum Eastwood joined calls for the drink's immediate removal.
"The drink's symbolism is hurtful to the true memory of Bloody Sunday and hurtful to the families who still bear the burden of the horrors inflicted that day," he said.
"I have written to the bar in question to request that the drink is immediately removed from sale.”