Marjorie Margolies has fallen farther behind her opponents in fund-raising for the 13th Congressional District primary race, leaving State Sen. Daylin Leach and physician Valerie Arkoosh jockeying for the No. 1 spot, according to campaign finance reports filed Tuesday with the Federal Election Commission.

Arkoosh and Leach each raised more than $1 million through the end of March. Margolies raised $843,332 and State Rep. Brendan Boyle $656,205.

Margolies has been the presumed front-runner, but remained in the middle of the pack in fund-raising with six weeks to go before the May 20 primary.

She has, however, been the leader in spending, leaving her campaign with only $160,000 cash on hand at the end of the first quarter.

Margolies' campaign said no one was available to comment due to Passover.

In the Eighth District, Rep. Mike Fitzpatrick raised more than $335,000 in the first quarter of 2014 and has more than $1.5 million in his coffers. The two Democrats vying to face him in the general election have about half that amount combined.

And in the Sixth District, primarily in Chester County, Republican Ryan Costello raised $344,450 in the first quarter of 2014 and had $305,308 on hand, his campaign said. Democrat Manan Trivedi had not filed a report as of 9 p.m. Tuesday.

In 2013, Arkoosh led the pack in fund-raising for the 13th District, which straddles Northeast Philadelphia and southern Montgomery County.

Leach surpassed Arkoosh in fund-raising for the first quarter of 2014, bringing in $335,660. But Arkoosh is still ahead with $1.16 million in contributions. Leach has $1.04 million.

Arkoosh also has received support from a political action committee that is spending $210,390 on radio ads in the six weeks before the election.

The race in the 13th District - where Rep. Allyson Y. Schwartz is stepping down to run for governor - has been heated from the beginning, with the four candidates carving out niches of support and funding.

Margolies, 71, of Wynnewood, has deep Washington ties from representing the district in the 1990s and having Chelsea Clinton as her daughter-in-law. At a fund-raiser last week, she shared the stage with former President Bill Clinton and many prominent local politicians.

The Clinton fund-raiser was not included in this quarter's report, but Margolies' campaign said it raised about $200,000.

Boyle, 37, of Northeast Philadelphia, has strong backing from local unions and the Philadelphia Democratic machine, but has struggled to keep up with his opponents.

Leach, 52, of Wayne, this week received a big endorsement from the state's largest teachers union. One of Pennsylvania's most liberal legislators, Leach has advocated for marijuana legalization, same-sex marriage, expanding Medicare, and other issues.

Arkoosh, 53, of Glenside, is an obstetric anesthesiologist whose campaign centers around her recent work pushing for the Affordable Care Act.

Arkoosh has reserved $400,000 and Leach $291,000 of TV airtime during the two weeks before the primary, according to their campaigns.

Among the Republican candidates for the 13th District, Dee Adcock raised $13,550 and gave his campaign a $50,000 loan. He had $47,188 cash on hand at the end of March.

The other Republican candidate, Beverly Plosa-Bowser, had not filed her quarterly report as of 9 p.m. Tuesday.

The Montgomery County Republican Committee is not endorsing either candidate, and the winner will face an uphill battle for the general election in the heavily Democratic district.

In the Eighth District, which covers Bucks County and a sliver of northeastern Montgomery County, Fitzpatrick outraised his two Democratic challengers, pulling in almost $337,000, campaign records show.

Fitzpatrick's cash on hand outpaces those of both Kevin Strouse and Shaughnessy Naughton by about $1 million.

Strouse, 34, a former Army ranger and CIA employee, raised about $165,000 this quarter - $115,000 from donors, $50,000 from a loan - and had $563,000 to spend.

Naughton, 35, who runs a family publishing business, raised nearly $125,000 and had $208,000 on hand.

Neither Strouse nor Naughton has run for office before. Strouse has the backing of the national Democratic Congressional Campaign Committee, while Naughton is endorsed by the Democratic women's group Emily's List.