Hartford - Gov. Dannel P. Malloy's approval numbers are showing a modest rebound from last year's low and most state voters endorse ending the ban on Sunday alcohol sales, according to an opinion poll released Tuesday by the conservative Yankee Institute for Public Policy.

Fifty-one percent of likely voters surveyed said they approve of Malloy's job as governor, with 46 percent disapproving. In a similar survey in June, conducted after Malloy signed into law the largest tax increase in Connecticut since the state income tax, only 42 percent approved of his job and 56 percent disapproved.

The new phone survey of 500 likely Connecticut voters was conducted this month by Pulse Opinion Research. It is the fifth voters' survey done on behalf of the Yankee Institute, which recently moved to East Hartford from its former headquarters near Trinity College.

The poll also found U.S. Rep. Chris Murphy, D-5th District, in a commanding lead over Republicans Chris Shays and Linda McMahon in election match-ups for retiring Sen. Joseph Lieberman's seat. Murphy beat professional wrestling matriarch McMahon 49 percent to 40 percent, and trumped former Congressman Shays, 45 percent to 39 percent.

Former Secretary of State Susan Bysiewicz, a Democrat, edged out McMahon (43 percent to 40 percent), but lost to Shays by a percentage point.

On policy issues, the poll found that voters strongly support ending prohibition on Sunday alcohol sales (62 percent to 31 percent).

There is support for abolishing the tenure system for public school teachers (61 percent to 24 percent), and the majority believe that teacher salaries should be tied to classroom evaluations and student performance rather than a teacher's formal education and years of experience (53 percent to 28 percent).

The poll found first-term U.S. Sen. Richard Blumenthal, a Democrat, with a higher approval rating (62 percent) than Lieberman, an independent (53 percent).

President Obama had a 53 percent approval rating, and beat both Mitt Romney (50 percent to 37 percent) and Newt Gingrich (56 percent to 35 percent) in presidential election match-ups.

Fergus Cullen, Yankee Institute's executive director, said the survey sample was largely representative of the state's voters but with slightly more registered Republicans.

j.reindl@theday.com