Premier Silvio Berlusconi has handed the Italian president his resignation, stepping aside and pledging to form a new government to strengthen a coalition weakened by a sluggish economy and opposition to Italian involvement in Iraq. Berlusconi's resignation on Wednesday brings to an end to Italy's longest-serving government since the second world war. He had been under pressure to resign since a stinging defeat in regional elections this month. President Carlo Azeglio Ciampi's office confirmed in a statement that Berlusconi had tendered the resignation of his cabinet and added that the government would stay on as caretaker. Earlier on Wednesday, Berlusconi addressed the Senate and informed the country of his plan to step down and form a new government and platform. It is up to Ciampi to designate a candidate to assemble a new government, or dissolve parliament and call early elections. Ciampi, who begins formal political consultations on Thursday, is expected to give Berlusconi the mandate to form a new cabinet. "The regional elections showed a clear sign of discomfort," Berlusconi told Senate. "I want to give an adequate political response." Government partners "have all demanded a new government, to be based on the same coalition," Berlusconi said. "I accept this challenge."