Weary Greece has braced for more painful austerity as Alexis Tsipras was sworn in as prime minister with a mandate to drive through unpopular reforms agreed with the nation's international creditors.  As a torrential downpour swept Athens on Monday, Tsipras took his second oath of office in eight months and got ready to unveil a cabinet that will have to apply tough economic reforms he signed onto in July.  "On my honour and conscience, I pledge to uphold the constitution and laws" of Greece, he said.  Earlier he told President Prokopis Pavlopoulos that a coalition government with the nationalist Independent Greeks party - his allies in the last cabinet - would be sworn in by Wednesday morning.  On the same day, Tsipras will travel to Brussels for a summit on the refugee crisis, where he will also represent Cyprus.  Some 310,000 migrants and refugees have landed on Greek shores from Turkey this year, most of them Syrians fleeing their country's civil war.  France, Germany, Spain and European Council president Jean-Claude Juncker on Monday pledged to help crisis-hit Greece, both on the economic front and in dealing with the worsening migrant crisis.  But EU partners wasted no time in reminding Greece to get down to work pushing through reforms laid out in a rescue package worth up to 86 billion euros ($A135 billion).  "Looking forward to swift formation of new government with strong mandate to continue reform process," Eurogroup president and Dutch Finance Minister Jeroen Dijsselbloem said.  From buying a loaf of bread to a visit to the doctor, pain lies in store as the new government readies to raise taxes and rewrite the economic rule-book in line with tough reforms demanded by the country's lenders in return for Greece's third international rescue in five years.  "There's a lot of work ahead and no time to lose," Juncker said.  "As you know well, you can count on the European Commission and on me personally to stand by Greece and support the new government in its efforts."  The economic to-do list was signed in July by Tsipras in a controversial deal that alienated anti-euro hardliners who then quit his Syriza party, stripping the premier of his majority and triggering Sunday's general election.  With all votes counted in the September 20 ballot, Syriza secured 35.46 per cent of the vote, close to an absolute majority of 145 seats in the country's 300-seat parliament.  Coalition partner ANEL is providing another 10 politicians.  Tsipras, who had justified the deal he signed in July with European leaders as saving Greece from a chaotic exit from the eurozone, said the election victory would "change the balance" in Europe and strengthen Greece's fight against endemic corruption and hidden wealth.  Do you have any news photos or videos?
Alexis Tsipras has been sworn in as Greece's prime minister for the second time as the country prepares for tough economic reforms.