Former trade and industry secretary Lord Young of Graffham on Tuesday said banks had scored an "own goal" more than 20 years ago when they "took the managers out of branches".
And in a House of Lords debate, shadow business minister Lord Mitchell said small and medium sized enterprises were suffering because of a lack of finance.
He said: "The end of relationship banking has harmed small businesses, who find that instead of local bank managers who understand them and can use judgement as to whether they should have credit such decisions are being made on a centralised basis, which is often also computerised."
Lord Green, former chairman and chief executive of HSBC, said it was "quite plain" that in some cases businesses were not getting the financing they needed "because the normal templates are being applied and inadequate imagination applied to the topic".
The Tory peer, who will leave the Government in December, said in reply to the debate: "What I think has happened - and this over not just the last three or four years of the financial and economic crisis but over the last 20 - is that the skill base of business banking in the high street banks has been deteriorating.
He said banks had responded by "disempowering those relationship managers".
But he said he regularly met bank chief executives and heads of commercial banking who were "determined to address the problem".