The association believes the move will present the industry with a series of challenges and a missed opportunity.
Robert Sinclair, chief executive of AMI, said: "The proposal to increase the cost of regulation from £10m to £25m adds another layer of expense to business that is already struggling like the rest of the economy.
“When combined with the higher hurdles that the FCA will impose on firms to reach full authorisation, we will undoubtedly have fewer firms paying these higher costs.”
Sinclair said the shortened eight week consultation periods on both the Treasury and FSA papers with Easter in the middle will make it difficult for trade bodies to fully consider, consult and feedback on all the issues.
He said: “As these proposals have been some time in the making this is disappointing.”
Sinclair said this does not leave enough time for firms to absorb the proposals, recognise the risks and react appropriately.
And he believes the proposed six month dual regime is unlikely to be long enough for legal certainty or practical implementation.
He added: “An opportunity missed is the silence on removing the need for mortgage broker to also hold the consumer credit permission.
“As many hold this only to cover simple reviewing or advising on settling unsecured credit surely this could be rolled into MCOB and avoid many firms who are already authorised by the FSA needing to go through this interim regime process.”