Politicians, trade union leaders and other activists were among hundreds who gathered in London today for a rally in support of Greece's new governing party Syriza, which swept to power last month with a pledge to fight the EU's austerity policies.
Members of left-leaning groups from across Europe gathered in Trafalgar Square as part of a pan-European wave of rallies and protests this weekend, with the London protest organised by the Greece Solidarity Campaign, Syriza London and other organisations including Left Unity.
Christos Giovanopoulos, an activist from Greek group Solidarity for All, told the crowd that the win for Alexis Tsipras' party had allowed Greece to escape a "regime of austerity and social barbarism".
"We understand that whatever happens in Greece depends not only on the Greek people, if we want to be successful we have to build an international movement and we have to bring the insurgency and the overthrow of the system everywhere," he said.
"We should do our best altogether to not allow the capitalists of Europe to unite against Greece, we should do altogether whatever it takes in order to give, to spread, the contamination of the revolt everywhere, to fight for the success of (Spanish left-wing party) Podemos and their movements in Spain, to fight for political change in this country, to strengthen our movements from below and strengthen our relationships and roots with the people. This is the secret."
Billy Hayes, the general secretary of the Communication Workers Union (CWU), who was representing the Trades Union Congress, added: "The TUC both in this country and internationally, has said this: the international financial institutions and European authorities need to respect the voice of the Greek people."
David Cameron last week warned that the stalemate between Athens and the eurozone over Greece's debts needs to be resolved to prevent damage to the British economy. After meeting Tsipras at a Council of Europe meeting in Brussels on Friday, Mr Cameron warned the longer the stand-off continued the worse it would be for the continent.
The UK has called for both sides in the dispute to act responsibly in an effort to avoid another economic crisis in Europe.
But a Greek exit from the eurozone appears inevitable and Britain must insulate itself from the effects, former Chancellor Ken Clarke has warned. The Tory big beast branded the new government in Athens "latter day Trotskyites", and said there was no way their demands could be met.
The Europhile MP's comments, in an interview with the BBC's Sunday Politics, came as talks continue between Greece and other member states over writing off some of the country's debts.
Asked whether the standoff would lead to a Greek exit - so-called Grexit - Mr Clarke said: "Just judging from the public statements of these latter-day Trotskyites who appear to have won the election in Greece, I can't see how that can be reconciled.
"I hope a very great deal of work is going on to minimise the impact on financial markets, on the United Kingdom - because it affects us just as much anybody else in the western world - to make sure that any knock-on effects of from their exit are minimalised, and knock-on effects on the Greek people, who are going to suffer more ... are also minimised as well.
"I can't see how you can sensibly avoid the Greeks defaulting and the Greeks having to leave the Eurozone. It's not anything to do with just the Germans, I can't see why any other states should take a huge multi-billion pound hit again for the Greeks so they can hire more civil servants, raise their minimum wage (and) scrap all their labour market laws."