Campaign group Republic said it was initially given permission to close off a street in London`s historic Covent Garden to stage the "Not The Royal Wedding" party on April 29 as Prince William and Kate Middleton tie the knot.
But the local council has now decided against allowing the road closure, meaning the party will not be able to go ahead.
Republic`s campaign manager Graham Smith blasted what he said was an attempt to ban a "peaceful, fun, family event" aimed at providing an alternative to the thousands of parties up and down the country that will celebrate the wedding.
"This is a disgraceful attack on the rights of republicans to make their voice heard and to hold a fun and peaceful event," he said.
"We can only assume this is a politically motivated ban and we will challenge it all the way."
He added: "We are now taking legal advice to see if we can overturn this decision in the courts."
But a council spokesman said it was "unaware of any local connection" between Republic, which campaigns for an elected head of state, and the area they had chosen for the party.
"Significant concerns" about disorder were also raised by the local community while local businesses feared the event would "directly contradict the royal wedding theme in terms of their merchandise," said the spokesman.
(Uu.SYS/G003/B002) 12-04-2011 18:36:39
Editor: Priyambodo RH
Copyright © ANTARA 2011
