AP: A Massachusetts congressman is asking BP to accept the government’s latest estimate of how much oil spewed from the company’s blown-out Gulf well as a basis to determine how much it may face in civil fines. Rep. Ed Markey sent a letter Wednesday to the head of BP’s U.S. operations telling him that the oil giant should legally own up to its obligations as one of the responsible parties for the spill. Civil penalties can be levied under a variety of environmental protection laws, …