Tory MP apologises for her failure to declare donations.
Charlotte Leslie, who represents Bristol North West, told MPs she was "unspeakably sorry" for not making the declarations in a timely manner.
We had sought a statement from Ms Leslie over concerns raised about Parliamentary Questions and other interventions relating to the Barrage project, whose main opponent has been Bristol Port, jointly owned by Tory donor David Ord.
Mr Ord's companies have made three donations totalling PS17,000 to Bristol North West Conservative Association since 2009, when Ms Leslie was the prospective candidate for the seat.
She won the seat from Labour at the general election in May 2010. On three occasions she has asked written questions about the environmental impact of the Severn Barrage and about public funding provided for research and promotional activities relating to it.
At the time she asked the questions she did not declare the donations made by Mr Ord's companies to her local party, as she should have done.
She belatedly declared the two donations made since she was elected an MP to the Register of Members' Interests last August.
She has made other interventions about the Severn Barrage during Commons business, again without declaring an interest.
Caerphilly Labour MP Wayne David said: "Charlotte Leslie has received huge financial backing from David Ord both privately and through the Bristol Port Company, and has then asked questions and made statements in the House of Commons about his business interests, yet did not declare an interest at the time the questions were asked and the statements made.
"By rabidly opposing the Severn Barrage development, in line with the position of Mr Ord, Ms Leslie has potentially scuppered a huge investment in Wales that could have created thousands of jobs.
Bristol North West is a closely contested three-way marginal, so all this money flooding into local Tory coffers could be the difference between winning and losing the seat. Voters in Bristol, South Wales and throughout the UK, deserve to know if there is a link between that funding and Ms Leslie's public position on the Barrage, and her unstinting support for Bristol Port Company.
"There are very serious questions about her conduct that the Parliamentary Commissioner for Standards should investigate as a matter of urgency."
Raising a point of order in the Commons on Tuesday evening, Ms Leslie said: "I am unspeakably sorry that despite all the efforts I made as a new MP to get things right I have nevertheless made this very serious error, and I went to reiterate my heartfelt apologies to the House and have sought the earliest possible opportunity to do so."
Later the MP issued a statement to us which said: "I am profoundly sorry for the mistakes which were made, in part due to my being registered dyslexic which, I have now recognised, required me to take on some extra support for matters involving detailed paperwork."
Charlotte Leslie MP