Leaders of a people’s veto effort to overturn Maine’s newly enacted tax law changes have submitted cartons of petitions seeking a referendum to state election officials. The Republican-led campaign called Still Fed Up With Taxes said Friday it turned in petitions containing more than 60,000 voters’ signatures. At least 55,087 signatures must be certified in order to force a June 2010 referendum. The law targeted by the people’s veto campaign extends the state’s sales tax to a number of currently untaxed services and raises the food and lodging tax. It also lowers the state’s top income tax rate from 8.5 to 6.5 percent for most Mainers. Friday’s submission of the petitions blocks the changes in the tax law, meaning they may not take effect on the Jan. 1, 2010 effective date.