"I've formed a new organization — PAC for a Level Playing Field — to advance our fight. Together we can do more, and we can support candidates across the country who believe in consistent accountability, investing in opportunity, and fighting for families and small businesses," she writes in the email.

Warren goes on to solicit donations from supporters, proclaiming that the PAC "won't be funded by big corporate interests. It will be funded by grassroots donors like you."

Warren was elected to the Senate with strong grassroots support, and solicited millions in small-dollar donations from supporters in Massachusetts and nationwide.

It's yet unclear where the PAC, which was launched late last year, will play in 2014, or what its fundraising goals will be for the cycle.

--This piece was posted at 11:16 a.m. and updated at 11:27 a.m. to reflect the nature of the PAC.