WASHINGTON (AP) — President Joe Biden is asking Congress to intervene to avert a potentially crippling freight rail strike before Christmas, even if it means handing a defeat to Democratic allies in the labor movement. The legislation urged by Biden and being voted on Wednesday by the House would impose a compromise labor agreement brokered by his administration that was ultimately voted down by four of the 12 unions that represent about 115,000 employees at the freight railroads. At issue is paid sick leave. Biden’s deal would leave out provisions on that while preventing a rail stoppage that would cost the economy $2 billion a day. But forcing the deal could also cost him his good standing among unions.