Speaking to PinkNews.co.uk, Mr Tatchell complained that Downing Street had agreed to keep the petition open until October but had "unilaterally declared it closed on June 6th".
He added: "The government's response ignores all of the issues raised in the petition apart from the cost of the visit.
"It has nothing to say about concerns expressed on women's reproductive rights, gay equality and the use of condoms to prevent the spread of HIV.
"In particular, it ignores the Pope's collusion with anti-Semitism by his rehabilitation of Holocaust denier Bishop Richard Williamson and his plan to make a saint of Hitler's Pope Pius XII.
"Amazingly, there is not a word in the government's response about the child sex abuse scandal and the Pope's role in its cover up."
Here's a link to the 'Protest The Pope' official website, which I have joined.
I intend to take part in the protests if I can afford to get to them. If not, I shall have to make do with a big sign in one of my front windows.