PROVIDENCE, R.I. — Rhode Island Secretary of State Matt Brown has laid off key campaign staff members amid questions about campaign financing that dried up his fundraising and threaten to end his candidacy for U.S. Senate.

"Our campaign is reorganizing and bringing in new people," campaign manager Tim Patterson wrote in a statement yesterday, saying the campaign would run "leaner and smarter" as it faces the five months until the Democratic primary.

The statement did not say who was laid off or explain why, and Patterson did not immediately return messages seeking comment.

But former Brown spokesman Matt Burgess said he was laid off Friday.

"The campaign is paring down, and I wish them the best of luck," Burgess said.

At least two other staffers — field director Rich Pelletier and finance director Bob Pilon — were laid off, according to a source with knowledge of the campaign, who spoke on condition of anonymity. Media consultant Matt MacWilliams of the Washington firm MacWilliams Robinson & Partners was also let go, the source said.

MacWilliams Robinson did not immediately return a call seeking comment. Pelletier and Pilon did not have telephone listings and could not immediately be reached.

The layoffs come about a month and a half after Brown acknowledged his campaign took $25,000 in donations from state Democratic parties in Hawai'i, Maine and Massachusetts, then steered its most generous donors to give money to those parties. Pelletier arranged the deals.

Watchdogs and political opponents accused him of trying to circumvent campaign finance laws, and the Republican parties in Hawai'i and Rhode Island sent a complaint to the Federal Elections Commission asking for an investigation. Brown denied wrongdoing, but returned the money.

The news made a big dent in Brown's campaign funds. His campaign announced last week that his fundraising badly lagged his opponents' in the first quarter, and he has just $35,000 cash on hand to last him until the September primary, far less than he would need to keep his full staff, according to reports filed with the Federal Elections Commission.

In the fourth quarter of last year, the most recent numbers available, payroll and related taxes for the campaign staff averaged about $50,000 per month. MacWilliams was paid more than $20,000 for the quarter.

Brown's major primary opponent, former Attorney General Sheldon Whitehouse, has more than $1.3 million on hand for the primary, according to reports filed with the FEC this month.

They are vying for the seat held by Republican Sen. Lincoln Chafee. Chafee faces Cranston Mayor Stephen Laffey in the Republican primary.