WASHINGTON (Reuters) – The U.S. Treasury on Thursday said the government should draw up a plan to begin recapitalising mortgage giants Fannie Mae and Freddie Mac, while calling on Congress to pen comprehensive housing reform that would allow the pair to be safely freed from government control.

The Treasury’s plan, released in a 53-page report, marks the first major effort to jump-start housing finance reform in Washington after a 2012 bid by the Obama administration fell flat. But by failing to commit to concrete timelines, and leaning on Congress to do the heavy lifting, the report may disappoint many investors hoping for a speedy overhaul of Fannie and Freddie.

Investors had been hoping the Treasury, in a bid to bolster Fannie and Freddie’s capital reserves, would give them the green light to start retaining the majority of their earnings. Instead, the report takes a cautious tone, recommending only that the government “consider permitting” them to retain more than the $3 billion in capital currently allowed.

On Thursday, a senior Treasury official stressed the need to rebuild Fannie and Freddie’s capital, but said a specific plan would still need to be carefully negotiated with the Federal Housing Finance Agency (FHFA), which oversees the mortgage giants.

The Treasury hopes that parallel to negotiating a capital plan with the FHFA, Congress will be spurred to take up broader housing reforms in coming months. Most importantly, it called for Congress to create an explicit guarantee for the companies’ mortgage-backed securities, although Washington housing lobbyists see such action as unlikely in the near term.

If Congress fails to create a new guarantee, the Treasury said it would use its existing investment in the companies to continue to provide a backstop, signalling it may be prepared to stand behind the companies indefinitely.

“The Trump administration is committed to promoting much needed reforms to the housing finance system that will protect taxpayers and help Americans who want to buy a home,” said U.S. Treasury Secretary Steven Mnuchin in a statement.

Fannie and Freddie, which guarantee over half the nation’s mortgages, have been in conservatorship since they were bailed out during the 2008 financial crisis and Washington has since struggled to devise a plan to get them back on their feet.

The Treasury holds warrants representing 80% of Fannie and Freddie’s common stock, as well as senior preferred stock. The preferred stock agreements guarantee Treasury a 10% dividend and allows it to sweep the firms’ profits into its coffers. That arrangement has left Fannie and Freddie with just around $3 billion of capital each, leaving taxpayers exposed to future bailouts.

In March, President Donald Trump asked the Treasury to develop a plan for administrative and legislative reforms to define a limited role for the government in the housing finance system, enhance taxpayer protections against future bailouts, and promote competition in the housing finance system.