Yesterday, Alliance for a Better Minnesota joined Americans United for Change and the Minnesota AFL-CIO to launch a new ad asking Minnesotans to call Governor Pawlenty at 800-657-3717 to ask him to promise to sign the election certificate, as required by law, if the Supreme Court rules that Al Franken won the Senate race last November.

Recently, Governor Pawlenty has "hemed and hawed" on whether he would sign the certificate, saying "I also would want to look at what the courts did with the case in terms of leaving issues for potential appeal, the strength of those issues, how directly and effectively they addressed them."

A recent poll from the Alliance for a Better Minnesota found that nearly six in 10 (59%) of Minnesotans believe that Norm Coleman should concede to Al Franken. The poll also shows that 64 percent of Minnesotans would have “serious doubts” about Tim Pawlenty if he were to refuse to sign a certificate of election -- as he is legally required -- if the Minnesota Supreme Court declares Al Franken the winner in the U.S. Senate.

Watch the ad below:

From CBS News:

[The ad pressures] Minnesota Gov. Tim Pawlenty to "act in the best interest of Minnesota" and certify Democrat Al Franken as the state's senator.

Franken was declared the victor in his battle against Norm Coleman for the Minnesota Senate seat following a recount and legal wrangling that has lasted for months. Coleman is now appealing the decision to the state Supreme Court.

"Most Minnesotans – including Republicans – believe that once the state Supreme Court rules, Governor Pawlenty should do his legal duty and certify Al Franken as our senator," an announcer says in the spot. "But the national Republican donors don’t want Minnesota to have our rightful representation in the Senate. The Republican Campaign Chairman, Texas Senator Cornyn, said Norm Coleman’s court challenges could take 'years' to resolve."

"Now Governor Pawlenty has a choice," the announcer continues. "Will he act in the best interest Minnesota or his own national political ambitions?"

These words then appear onscreen: "Call Governor Pawlenty at 800-657-3717. Ask him to put Minnesota’s interest ahead of political ambition."

The stakes for the Minnesota seat increased this week with Pennsylvania Sen. Arlen Specter's announcement that he is becoming a Democrat, effectively giving the party 59 votes in the Senate. If and when Franken is seated, the Democrats will have 60 votes and a filibuster-proof majority – though that would require the votes of all 60 senators who caucus with the party, which is far from a sure thing.

National Republicans, who would prefer to keep Franken from becoming a voting member for as long as possible, have raised money for Coleman's legal effort.

Americans United For Change's Jeremy Funk says the group is spending "five-figures" to air the spot on cable. He said it will run on cable in the twin cities and Rochester media markets starting tomorrow and is going to run through the week.