This is a blatant and obscene abuse of power by a criminal cabal surrounding Mugabe Gordon Brown
The Lisbon Treaty aims to streamline the decision making of the European Commission - but critics say it will transfer more power to unelected officials in Brussels.
At present, members of the Zimbabwean government regime are banned from EU-related travel in the 27 member states.
Divisions over the treaty, in the wake of the Irish referendum, has overshadowed the Brussels summit - a decision on what to do next is expected to be postponed until October.
On the sanctions question, Mr Brown said: "We have reserved the right to look at this again. Our basic concern is that the election should be free and fair and action must be taken to stop the violence now."
At the summit in Brussels President Sarkozy, who will take over the rotating EU presidency in July, said the EU would not be able to expand further if the treaty was not ratified.
The prime minister added: "State TV has stopped any pretence of balanced coverage, the opposition is intimidated and its secretary-general under arrest.
Abortion concerns
"This is a blatant and obscene abuse of power by a criminal cabal surrounding Mugabe. It is a criminal regime."
But the British government has said there will be no "bulldozing" the Irish into voting again on the treaty.
Speaking to the BBC on Friday, Mr Miliband said: "The absolute guarantee is that unless there is an agreement from all 27 countries to the treaty it can't come into force and also a guarantee that any change in the Irish constitution requires the acceptance of the people."
They will never take 'no' for an answer Nigel FarageUK Independence Party
He strongly denied suggestions that the British position was that the treaty could be "finessed" to address Irish concerns - then put back to them for a second vote.
Mr Miliband said that was "not true" and said there were "relevant points" that the Irish government had to have time to address - as many of the issues raised by the "no campaign" in Ireland, such as abortion and conscription, "didn't have anything to do with" the treaty.
He added: "I want the Irish to decide what they think is the right thing ... I think the right thing for Britain is to pass the treaty as we have, I think the right thing is for the seven other countries that are still in the middle of their ratification processes to continue.
"They could decide yes or no - that's completely reasonable."
"It's then for the Irish government to decide about their next steps, unless the Irish people agree to change in the constitution then the treaty can't come into force. It couldn't be simpler."
But UK Independence Party leader Nigel Farage, who campaigns for Britain to leave the EU, told BBC One's Question Time: "We have a political class in Europe, they're virtually indistinguishable from each other and they have decided that we are going to have this big strong global player called a European Union."
He added: "They will never take 'no' for an answer and the peoples of Europe are saying 'we don't want this' and at some point that vacuum is going to be filled."