A new poll commissioned by his challenger’s campaign showed Rep. Phil English (R) trailing in his bid for an eighth term by a single percentage point.

The poll showed businesswoman Kathy Dahlkemper (D) leading English 41 percent to 40 percent, with 19 percent undecided.

English could be in one of the toughest races of his career against Dahlkemper, a political novice who won a four-way primary in April. Though the northwestern Pennsylvania district voted narrowly for President Bush in 2000 and 2004, English went up on television with his first advertisement in June — much earlier than in previous cycles.

The poll also showed English with a 35 percent job-approval rating, compared with a 52 percent negative job-approval rating. The Momentum Analysis poll surveyed 400 likely voters in the district from July 8 to 10. The margin of error was 4.9 points.

“Phil English faces the daunting task of defending George Bush’s record in a year where the president is incredibly unpopular and in an area where there has been a surge in Democratic participation,” Democratic Congressional Campaign Committee spokeswoman Carrie James said.

However English spokesman Adam Beebe took issue with the poll, saying it was “obviously construed in a manner to help her attempt to raise money and continue her negative campaign against” English.

“We were made aware of this poll last week when we started receiving numerous calls from upset constituents who had been called,” Beebe said. “Our constituents relayed to us they were in the field testing an extremely negative [message] and what has been described to us as ‘outright smears’ against Phil.”