NEWLY ELECTED SEN. ED MARKEY leads Republican Scott Brown by 5 points in a new poll, a significant shift from December when Markey was trailing Brown in a head-to-head matchup by 18 points.

The poll by the MassINC Polling Group indicates Markey is currently leading Brown by a 43-38 margin, yet Brown still holds the edge in favorability. The poll indicates Brown’s favorable/unfavorable ratio is 45-29, compared to Markey’s 36-29 ratio. Markey’s five-point lead in the head-to-head matchup is a major reversal from a December 2012 MassINC poll, which had Brown leading Markey by 18 points.

The MassINC Polling Group surveyed 500 Massachusetts residents 18 and older from July 17 to July 20. The telephone poll targeted cell phone and landline users and has a margin of error of plus or minus 4.4 percent. The MassINC Polling Group is a for-profit subsidiary of MassINC, the nonprofit think tank that owns CommonWealth magazine.

After losing his Senate seat to Elizabeth Warren last November, Brown declined to run for the seat vacated by John Kerry, who was appointed secretary of state by President Obama. Brown signed on as a commentator with Fox News and took a job with the law firm Nixon Peabody. He has been coy about his political future, leaving the door open to running for various government jobs in Massachusetts and possibly even New Hampshire.

Brown could merely be biding his time until 2014, when he could challenge Markey for his seat and the chance to win a full six-year term in the Senate. “I could beat Ed Markey, absolutely,” Brown told Fox News in June.

The Markey-Brown results were part of a quarterly survey by the MassINC Polling Group. The poll indicates consumer confidence in Massachusetts is faltering, with 41 percent of those surveyed believing bad economic times are coming over the next 12 months. The poll indicates 47 percent of those surveyed expect “periods of widespread unemployment or depression.” Both numbers represent a 10 percentage-point increase since the last quarterly poll in April.