WASHINGTON (Reuters) - The U.S. Supreme Court on Tuesday asked both sides for new information in a challenge by Christian nonprofit employers to a mandate under President Barack Obama’s healthcare law to provide insurance to female workers covering birth control, indicating the justices are struggling to decide the closely watched case. The court’s order requested more information on how contraceptive coverage can be obtained “in a way that does not require any involvement” by these employers, who object to the requirement on religious grounds. The Supreme Court suggested that one way to resolve the case would be for insurance companies to have the job of notifying employers about the availability of contraception coverage if their religious employer does not provide it. In the oral argument in the case last week, the shorthanded eight-justice court appeared split, raising the possibility of a 4-4 decision that would leave in place lower court rulings that backed the Obama administration. The court, now evenly divided with four conservatives and four liberals, is one justice short following the death of conservative Antonin Scalia in February. The order in the contraception matter came just hours after the court deadlocked 4-4 in another major case: a conservative challenge to a critical source of funding for public sector unions.. The request for additional information could both delay a ruling and indicate the court is seeking a compromise that a majority of justices could back. A ruling is due by the end of June. Dubbed Obamacare, the Affordable Care Act was passed by Congress in 2010 over unified Republican opposition and is seen as Obama’s signature legislative achievement. But congressional Republicans have repeatedly sought to repeal it and conservatives have launched numerous legal challenges, with the Supreme Court in 2012 and 2015 issuing high-profile rulings preserving it. In the current case, Christian nonprofit employers objected to a 2013 compromise offered by the Obama administration that allowed entities opposed to providing contraception insurance coverage to comply with the law without actually paying for the required coverage. Groups can certify they are opting out of the mandate by signing a form and submitting it to the government. The government then asks insurers to pay for contraception. The challengers primarily are Roman Catholic including the archdiocese of Washington and the Little Sisters of the Poor order of nuns that runs care homes for the elderly. They contend the accommodation violates their religious rights by forcing them to authorize the coverage for their employees even if they are not paying for it. 