May fundraising reports filed last week by the Congressional campaign committees largely showed parity between the two parties for the month.

While the National Republican Senatorial Committee out-raised its Democratic counterpart by about $1 million, that was the same amount that the Republican National Committee transferred to the NRSC during the month.

The NRSC raised $4.5 million compared with the Democratic Senatorial Campaign Committee’s almost $3.5 million. Even without the financial assist, the GOP committee still had a slightly better May than the Democrats did.

According to numbers that were due to be reported to the Federal Election Commission on Saturday, the DSCC has a slight cash-on-hand lead with $4 million to the NRSC’s $3.7 million.

But the NRSC was able to pay off its remaining debt from the 2008 cycle in April while the DSCC was $4.2 million in the hole as of May 31.

Five months into the 2010 cycle, the DSCC and NRSC are nearly equal in total fundraising, with the Democratic committee having brought in almost $17 million in total receipts and the Republican committee having raised $17.2 million.

On the House side, Democrats out-raised their GOP counterparts by about $200,000, but they still carry roughly $2 million more in debt than Republicans.

The Democratic Congressional Campaign Committee raised more than $3.4 million in May and spent close to $2.5 million. The DCCC ended May with more than $5 million in the bank and a debt of more than $6.6 million. At the end of April, the DCCC reported $4 million in cash on hand and $7.3 million in debt.

The National Republican Congressional Committee collected more than $3.2 million in the month of May, including a $1 million transfer from the RNC. The committee knocked down its debt to $4 million — $1 million less than at the end of April.

The NRCC spent about $3.2 million in May and ended the month with $3.7 million in cash on hand.

The NRCC has raised $14.4 million so far this year, while the DCCC raised significantly more — almost $24 million — in the first five months of 2009.

Both parties held major joint fundraising dinners this month featuring high-profile party leaders, and it will be interesting to see if those events are reflected in their June reports.