* Greece must honour its obligations says Spanish PM
* Spain part of "axis of powers" against Athens - Greek PM
* Tsipras: conservatives fear rise of own leftist parties
* Portuguese leader denies taking hard line on Greece (Adds Greek government official's comment)
By Costas Pitas and Sonya Dowsett
ATHENS/MADRID, March 1 (Reuters) - Spain's centre-right Prime Minister Mariano Rajoy hit back on Sunday against accusations from Greece's leftist premier that Spain and Portugal had led a conservative conspiracy to topple his anti-austerity government.
Greek Prime Minister Alexis Tsipras said Spain and Portugal had taken a hard line in talks on the euro zone extending the Greek bailout programme because they feared the rise of the left in their own countries.
Greeks have directed much of their fury about years of austerity dictated by international creditors at Germany, the biggest contributor to their country's 240-billion-euro bailout.
But in a speech on Saturday to his Syriza party, which won an election on Jan. 25, Tsipras turned on Madrid and Lisbon, accusing them of attempting to sabotage the negotiations for political reasons.
"We found opposing us an axis of powers ... led by the governments of Spain and Portugal which for obvious political reasons attempted to lead the entire negotiations to the brink," Tsipras said.
"Their plan was and is to wear down, topple or bring our government to unconditional surrender before our work begins to bear fruit and before the Greek example affects other countries," he said, adding: "And mainly before the election in Spain."
Rajoy said Spain had shown solidarity with Greece as part of the euro zone by helping with its bailout and urged Greece to fulfil its obligations and keep its promises.
"We are not responsible for the frustration generated by the radical Greek left that promised the Greeks something it couldn't deliver on," he said.
The Greek government on Sunday sought to play down the row, saying Tsipras was obliged to tell Greeks how the negotiations went and that his comments had been misinterpreted.
"The new Greek government does not categorize European countries and people as friends or enemies," a government official told Reuters. "Any misinterpretation of the Greek prime minister's speech does not help the dialogue."
Spain, Portugal and Ireland have faced stringent austerity programmes and structural reforms in return for European assistance, in Spain's case for its troubled banking system.
Tsipras rejected criticism that Athens had staged a climbdown to secure an extension of its financial lifeline from the euro zone, saying anger among German conservatives showed that his government had won concessions.