President Barack Obama Monday made a last-minute appeal to Massachusetts voters to support Rep. Ed Markey, who faces Republican Gabriel Gomez in a special Senate election Tuesday.

The winner takes the seat formerly held by Secretary of State John Kerry.

Polls show Markey leading by a hefty margin, but the Democratic Senatorial Campaign Committee was taking no chances, sending a mass email to potential voters from the president. The email also solicited contributions to help Democrats in next year's mid-term elections.

"I need Ed Markey in the U.S. Senate. And that's why I need you," reads the email. "Right now the other side is running dishonest attack ads against Ed. They think a last-minute surge will tip the scales. If we lose tomorrow, they'll be one step closer to obstructing everything you and I stand for."

The email urges recipients to "pitch in $3 to fight for Ed and Democrats like him," saying, "The stakes are too high to give up now."

It continues, "We can't let the nation's most powerful special interests buy this election and others like it and roll back what we stand for."

"What happens tomorrow depends on what we do today. This is in your hands now. I'm counting on you to help us," the email concludes.

A Suffolk University poll released Monday showed Markey leading Gomez by 10 points, while a survey released Saturday by The Republican/MassLive.com with WSHM-TV in Springfield had Markey up 8 points.

The Suffolk poll found 52 percent of respondents backing Markey and 42 percent for Gomez. The Republican/MassLive.com poll found Markey with 49 percent, Gomez with 41 percent and 9 percent undecided.

Markey entered the race with an advantage because registered Democrats outnumber Republicans in Massachusetts 3-to-1. The Republican/MassLive.com poll found Gomez is drawing about 12 percent support from Democrats, compared to 7 percent of Republicans who support Markey.

Gomez leads by 15 points among independent voters.