President Bush and Democrat John Kerry (search) remain locked in a tight contest in Pennsylvania, a key battleground state that Al Gore won by 4.2 percentage points in 2000.

Kerry had the backing of 44 percent, Bush 43 percent and independent candidate Ralph Nader 7 percent in the Quinnipiac University poll released Thursday.

In May, Kerry had 44 percent and Bush 41 percent — a statistical tie. Bush had a slight lead in the state in April.

In a two-way matchup, Kerry leads Bush 49 percent to 43 percent in the state with 21 electoral votes.

The economy is the most important issue for Pennsylvania voters, with just over four in 10 saying it is their top issue. Just over a fourth said Iraq, and another fourth said terrorism.

Voters feel Kerry would do a better job on the economy by 50 percent to 43 percent. Bush and Kerry are virtually tied on who could best handle Iraq. Bush has the advantage on terrorism by 53 percent to 38 percent.

The poll of 839 registered voters taken June 21-22 has a margin of sampling error of plus or minus 3.5 percentage points.