Liberal Democrat deputy leader Simon Hughes apologised to the Commons today after it was found he failed to properly declare donations in the register of members' interests.
The Standards and Privileges Committee said it found no evidence of attempts to conceal the six donations because they were declared to the Electoral Commission, but said an MP of Mr Hughes's experience should have properly updated Parliament.
Making a personal statement, Mr Hughes said: "I take full responsibility for these failures and apologise unreservedly to the House."
Mr Hughes said: "A report has been published today by the Standards Committee following an investigation by the Parliamentary Commissioner for Standards into complaints made about me.
"I'm grateful to the commissioner (Kathryn Hudson) for her thorough, courteous and professional work and for the report, and to the committee's chair and its members and their clerk for dealing with this matter in a very fair and efficient way.
"I accept entirely their conclusions. From the beginning, I believed I had not breached the lobbying rules and I am grateful and relived the commissioner and the committee have rejected these complaints.
"The committee has found there was no attempt to conceal any donations which were all reported to the Electoral Commission and in the public domain but that I failed to register in the register of members' financial interests some donations to my local party, that I failed to make declarations in debate, and in connection with one meeting in relation to two of these donations and that I registered two donations late.
"I have of course rectified this and apologised from the outset to the commissioner and to the committee.
"Although the commissioner found none of these breaches of the rules was intentional, I accept entirely the commissioner's finding and the committee's finding that I was not as attentive to these matters or as careful as I should have been, and therefore in these ways failed properly to observe the code of conduct and I did not sufficiently seek advice from the registrar.
"I will immediately register the outstanding interests as the committee recommends. I take full responsibility for these failures and I apologise unreservedly to the House."
Following the inquiry by Ms Hudson, the committee found that Mr Hughes failed to register donations to his local party totalling more than £30,000 over a six-year period.
Four were from IPA Consulting Ltd, one came from City Cruises Plc, and one from Southwark Metals Ltd.
The committee cleared Mr Hughes of the more serious complaint that he engaged in paid lobbying over a meeting his office arranged with local councillors and MPs concerning the development of a tract of land in which Southwark Metals had an interest.
Nevertheless, it did criticise Mr Hughes for failing to declare an interest both when he set up the meeting and when he was chairing it.
Recommending that Mr Hughes should make a personal apology to the House, the committee said: "We are concerned that a Member of Mr Hughes's seniority and experience should have failed to observe the code of conduct over such a long period and failed to seek advice from the registrar."
The committee also expressed concern that it had taken Ms Hudson almost a year to complete her inquiry.
"We do not believe that Mr Hughes was attempting to obstruct or delay the inquiry in any way, but it took some time before the commissioner was able to gather all the information she needed to conclude the case," it said.
"Members involved in an investigation must respond to the commissioner's inquiries promptly and as fully and accurately as possible."