Chancellor George Osborne has been urged to "resist buckling" under the pressure of "intense lobbying" by banks ahead of moves to reform the financial sector.
The Financial Services Bill is due go before the House of Lords in the next fortnight, paving the way for the abolition of the Financial Services Authority (FSA) and the birth of two replacement organisations.
Mr Osborne is also due to publish a White Paper on the Banking Reform Bill, introducing a raft of measures to prevent a recurrence of the banking collapse.
Consumer charity Which? called on the Government to keep "ordinary people" in mind when pushing through the bills amid criticism from banks who have claimed the reforms will prompt large financial institutions to leave the UK.
Richard Lloyd, executive director of Which?, said: "We have seen intense lobbying from the banks since the Independent Commission on Banking report, including a crescendo of scaremongering over recent weeks on the risk of the end of 'free banking' and of big financial institutions leaving the country. The Chancellor must resist buckling under this pressure."
The Independent Commission on Banking (ICB) was set up by the Government in the wake of the financial crisis to review the embattled sector.
The commision, chaired by Sir John Vickers, published a report last September which looked into ways of avoiding major bailouts in the future. It made a series of recommendations including forcing banks to ring-fence their retail arms from riskier investment banking divisions.
Other proposals include making it easier for customers to switch their account from one bank to another by September 2013 to boost competition in the sector and requiring banks to increase capital reserves to make them more resilient to financial crises.
Mr Lloyd added: "Plans to ring-fence risky investment banking from essential consumer retail banking must not be derailed by vested interest and must stick to the proposed timetable so that consumers never again have to foot the bill for a banking bailout that even the banks admit will not be repaid in our lifetime.
"Seventy-one per cent of people told us they are not confident the Government will act in the consumer's best interest when implementing banking reform. Without strong action that shakes up the culture of British banking consumers will continue to pay the price."