The national regulations were brought forward after Edinburgh North & Leith Labour MP Mark Lazarowicz tabled a private member's bill, prompted by fears of a disastrous oil spill.
But he said the controls – due to come into force in April next year – were now at risk as a result of lobbying by the shipping industry and a motion at Westminster proposed by Tory and Liberal Democrat MPs.
Mr Lazarowicz said: "The need for regulation is being highlighted every night in the pictures on TV of the disaster in the Gulf of Mexico.
"I was determined to make sure that kind of tragedy doesn't happen in the Firth of Forth by pressing for transfers to be confined to licensed ports where the proper safety measures are fully in place.
"Oil from the Torrey Canyon disaster off the Welsh coast is still killing wildlife 40 years later. I am fighting to prevent the new regulations being scrapped before they have even been given a chance to work."
A controversial proposal by SPT Marine Services to transfer 7.8 million tonnes a year of Russian crude oil between ships in the Forth was withdrawn in February 2008 after the government promised regulations.
Now four MPs from the south-west of England – Tory Sarah Newton and Lib Dems Andrew George, Stephen Gilbert and Mike Hancock – have tabled a Commons motion calling for the regulations to be scrapped.
Mr Lazarowicz said: "Whether this move has any support from the new government we don't know, but it is concerning there are MPs wanting to vote down the regulations."
He said the shipping industry had been lobbying against the regulations, apparently believing it was now operating in a more sympathetic environment. "All the industry bodies were consulted at the time. It is concerning after the previous government went through extensive consultation that there should now be a last-minute attempt to stop the regulations coming into force."
Mr Lazarowicz has tabled his own motion supporting the new controls.
And Lothians Green MSP Robin Harper has tabled a similar motion in the Scottish Parliament.
He said: "The regulations passed by Westminster in April to restrict ship-to-ship oil transfers are essential if this country is to meet its international legal obligations to protect the environment. We have long campaigned for better regulation and proper control over ship-to-ship transfers.
"Such operations carry a huge and unacceptable risk, and are a tactic the companies only use to save themselves a day or two of transit time. Now, just as those regulations are finally delivered, it's disturbing to see Lib Dem and Tory MPs encouraging ministers to backtrack, especially when the disaster in the Gulf of Mexico shows how high the price can be when corners are cut by the oil industry."