Rome, May 17 - The secretary of one of the two main parties backing Enrico Letta's new right-left government said he was "extremely satisfied" with its first move to reform the unpopular IMU property tax. "The government's first ball has scored," said Deputy Premier and Interior Minister Angelino Alfano of Silvio Berlusconi's People of Freedom (PdL) party, which backs the Democratic Party's Letta. Berlusconi had threatened to pull the plug on the unprecedented executive unless IMU was scrapped and last year's take paid back. Letta said Friday a June instalment would be put back for several months on both homes and businesses, satisfying the PdL pending a wider overhaul. The premier has not said IMU will be abolished, however, given EU-mandated budget restraints.