The website will capture experiences of SMEs, including those that have approached RBS and its subsidiary NatWest. These will be fed in to a review of lending practices being undertaken by the group.

"Responses will inform the findings and conclusions of our independent review, which aims to identify steps that NatWest and RBS can take to enhance support for SMEs and the economic recovery, while maintaining safe and sound lending practices," said a spokeswoman.

Chief executive Ian Cowie said: "We’re challenging ourselves to do the best possible job of supporting SME growth, so we need to hear from businesses to make sure we are tackling the things that will make a difference for them.

"There are many opinions on what banks could do to lend more but the most important are those from businesses themselves – this is their chance to have their say."

BPIF chief executive Kathy Woodward said: "Feedback on what is happening at grass-roots level is vital if we are to effectively lobby. While a website is great for giving some quantification of the issues, what is important is a real shift in commitment to supporting business risk rather than applying a set of rules.

She added: "It is really important SMEs have access to affordable finance for growth, consolidation and working capital, and that the balance between risk and return isn’t all one sided in favour of the banks."

A spokesman for the Federation of Small Businesses (FSB) in Scotland said RBS’s approach to small business lending was crucial because of its large share of the business banking market. He called on FSB members to contribute to the review regardless of who they banked with.

Last month RBS appointed Sir Andrew Large and management consultant firm Oliver Wyman to undertake an independent review of the standards and practices used by RBS and NatWest, for small and medium sized business lending in the UK.