Mark Critz, the Democratic nominee in the special election to fill the late Rep. John Murtha’s (D-Pa.) seat, has an 8-point lead over Republican Tim Burns, according to a polling memo obtained by Roll Call.

Critz led Burns 45 percent to 37 percent in the Global Strategy Group poll, a lead that the pollsters note is greater than the 3-point advantage Critz posted in their mid-April survey.

However, this is the only recent poll that showed Critz with a substantial lead in the May 18 special election. Two surveys from mid-April showed a statistical tie or Burns ahead, and a recent poll done for the Democratic Congressional Campaign Committee’s independent expenditure arm also showed the race to be a dead heat.

The Global Strategy Group polling memo boasts that Critz’s favorable rating has increased from 39 percent to 60 percent in the two-week period since their last tracking poll. Meanwhile, the memo showed Burns’ unfavorable rating increased from 8 percent to 24 percent.

The survey polled 400 likely special election voters from April 27-29. It had a 5-point margin of error.