In a filing on Monday to a US court in Texas, the British government suggested the law may not have been applied fairly to BP.
It also warned that the US Environmental Protection Agency (EPA) ban on the company creates "harmful regulatory uncertainty" that might discourage other companies from cooperating with regulators.
"Regulators should apply the law fairly and predictably lest their actions erode global public trust in the institutions and individuals involved. In this case, Her Majesty's Government is concerned that these reasonable standards have not been met," it said in the filing.
In addition, the government said, the EPA ban "risks creating a powerful disincentive to cooperation in times of crisis."
"Corporations may think twice before agreeing to accept responsibility, to perform remedial work, or to negotiate a plea agreement if such efforts are not taken into account when the time comes to mete out other sanctions."
BP has paid billions of dollars in fines and compensation over the 2010 Deepwater Horizon disaster, which left 11 people dead and sent millions of barrels of oil churning into the Gulf of Mexico.