Harvard Law school Professor Elizabeth Warren will announce her candidacy for senator of Massachusetts Wednesday, ending months of speculation over whether she would run in the 2012 election.

Warren, best known for her work on consumer financial protection, will battle current Senator Scott P. Brown who is seeking a full six-year term next year.

Warren launched an exploratory committee in August to test the political waters surrounding a potential Senate bid, sparking excitement among Democrats who were stunned two years ago when Brown managed to win the seat formerly held by Edward M. Kennedy ’54-’56 for nearly five decades.

“The pressures on middle-class families are worse than ever, but it is the big corporations that get their way in Washington,” Warren said in a statement today. “I want to change that. I will work my heart out to earn the trust of the people of Massachusetts.”

Warren will not make any formal announcement of her candidacy and will launch her campaign by meeting with voters in Boston Wednesday morning. Later in the day she will make stops around the state, including New Bedford, Framingham, Worcester, and Springfield.

Warren entered the national spotlight after the 2008 financial crisis when she became a prominent advocate for American consumers, pushing for increased regulation of Wall Street and transparency in the financial services industry.

Though the recently created Consumer Financial Protection Bureau was her brainchild, Warren was unable to lead the agency because Senate Republicans made clear that they would block her confirmation if Obama nominated her as director.

In an end run around Senate Republicans, President Obama chose to appoint Warren to a special advisory position that would allow her to oversee the design of the bureau while avoiding Senate confirmation. Ultimately, she was passed over as the bureau’s director.

Warren will face a tough race against Brown, who has already raised about $10 million in campaign funds. Last month, the Brown campaign called on its supporters to donate in anticipation that “the Democratic political establishment is going to pull out all the stops next year.”

Warren is expected to have considerable financial and political support from national Democratic networks. In the past several weeks liberal advocacy organizations including EMILY’s List and the Progressive Change Campaign Committee have begun collecting funds and organizing volunteers on Warren’s behalf.

During the campaign Warren will likely have to contend with Republican charges that as a Harvard professor she is out of touch with the average Massachusetts voter.

Brown—who emerged from the state senate to beat out Martha Coakley in 2010’s special election—has billed himself as the average, rugged man who drives a pick-up truck.

“[Democrats] are so obsessed with winning this seat back that Washington elitists are trying to push aside local Democrat candidates in favor of a liberal Harvard professor from Oklahoma,” the Brown campaign wrote in a recent letter soliciting donations.

Though Warren speaks openly about her time at Harvard, she has gone to great lengths to emphasize that she is also the child of a custodian and speaks frequently about her modest beginnings on “the ragged edge of the middle class.”

Warren also may be attacked for her lack of political experience and narrow range of expertise. Government professor Roger B. Porter noted her “little experience in elective politics.” But he praised her “conviction that large financial institutions engage in predatory and anti-consumer practices,” noting, however, that he disagreed with Warren's policy prescriptions.