Updated

A federal judge has asked for written arguments and responses from both sides in a case that accuses federal election officials of opening loopholes in the new campaign finance law.

U.S. District Judge Colleen Kollar-Kotelly, moving the case forward after a U.S. Supreme Court ruling upheld most of the new regulations, ordered written arguments by Feb. 27 and responses to opponents' claims by March 31.

At issue are the case's merits and whether the two lawmakers suing the Federal Election Commission (search) - Rep. Christopher Shays, R-Conn., and Rep. Martin Meehan, D-Mass. - have legal standing to challenge the commission's interpretation of the law.

Shays and Meehan are trying to overturn several commission rules telling political players how it will enforce the new law.

Those include FEC rules on the law's ban on the use of corporate, union and unlimited contributions - known as soft money (search) - in federal elections. Shays and Meehan are also challenging the commission's reading of restrictions on the use of corporate and union money for political ads and on coordination among campaigns, interest groups and political parties on election spending.

The lawmakers argue the FEC has weakened the law's restrictions and that it exceeded its authority. The FEC contends Shays and Meehan lack legal standing to challenge the rules and that the commission's interpretation of the law is appropriate.

Kollar-Kotelly has not yet decided whether she will give each side a chance to argue at a court hearing, or will rule based on the written arguments alone. The Washington judge set the case schedule Wednesday.

The Supreme Court last month upheld most of the law, including its soft money ban and political advertising (search) and coordination restrictions.