Prime Minister Gordon Brown apologised yesterday over controversial emails sent by his aide Damian McBride.

He revealed he had been “horrified” and “very angry” when he first learned about the emails. Mr Brown said: “I take full responsibility for what happened. That’s why the person who was responsible went immediately.”

He said: “I have said all along that, when I saw this first, I was horrified, I was shocked and I was very angry indeed. I think the most important thing we do is reassure people everything is being done to clean up politics in our country.

“I wrote to the people who were affected by it and expressed very deep regret for what happened.

“The person who was responsible went immediately and lost his job and I have ensured that there are new rules so this can’t happen again. We have done everything in our power to deal with this.”

Mr Brown was criticised earlier in the week for failing to say sorry in a letter he wrote to those targeted by the disgraced aide.

Meanwhile, the West Midlands minister dragged into the “smeargate” scandal spoke of his misery as he fights to save his career.

Tom Watson (Lab West Bromwich East) was on holiday with his family in the West Country when he found himself under fire over revelations that a Downing Street official planned to spread anonymous slurs about Conservative opponents.

He has strongly denied claims that he conspired with Mr McBride, Mr Brown’s head of strategy and planning, to create a website called “RedRag” to smear Tories.

The suggestion that Mr Watson was involved came from a Conservative activist called Iain Dale, who made it on his website - before admitting he was mistaken and apologising.

But the claim had already been picked up by sections of the media and internet “bloggers”, and Conservatives have demanded an inquiry to determine whether Mr Watson was involved.

Mr McBride has already been forced to resign from his Number 10 job but Mr Watson, a Minister in the Cabinet Office, called in libel lawyers Carter-Ruck to issue a statement on his behalf, making it clear that he had not been copied in on or been aware of an email from Mr McBride setting out plans for the website.

Mr Watson said: “It has been an utterly miserable week.

“I have been trying to give my family a break. The atmosphere feels like we have been mauled by a pack of wolves.

“To restate, for the hundredth time, I had no knowledge and therefore no input into the Red Rag website, and will vigorously defend myself to anyone who suggests different.”

The MP, his wife Siobhan and two young children went on holiday on Easter Monday, but have found themselves unable to enjoy the break, he said.

One of the claims made about Mr Watson, which he insists is untrue, is that he was in some way involved in managing Mr McBride in his role as the minister responsible for the civil service or as one of Mr Brown’s political allies.

Mr Watson said: “I didn’t sit next to him, as some reports have said. I didn’t share an office with him, and never have. I never gave him instructions and he never asked me for permission for anything he did. I wasn’t his manager.”