The Democratic Senatorial Campaign Committee announced raising $5.6 million in May, leaving the committee with $28.3 million in cash on hand.

The National Republican Senatorial Committee has not yet announced its May fundraising totals, which are due to be filed today.

Control of the Senate is up for grabs in November. Democrats, who are defending 23 seats compared with 10 for Republicans, currently hold a 53-47 majority.