Just when Labour was rehearsing its attacks on the Tories as the "nasty party", welfare minister Lord Freud has suggested some disabled workers are "not worth" the minimum wage and could be paid just £2 an hour.

A recording of his comments at a Conservative party fringe meeting were used by Ed Miliband in his first question time clash with the prime minister of the new parliamentary session and had David Cameron firmly on the back foot.

Cameron said the remarks were not the policy of the government or any member of the government, seeming to ignore the fact Freud was a minister.

Fellow minister Esther McVey called on her colleague to "explain himself" and said the remarks would "haunt him."

In the dog days of this government the Conservative party is going back to its worst instincts – unfunded tax cuts, hitting the poorest hardest, now undermining the minimum wage. The nasty party is back.
- Ed Miliband

And within a couple of hours, Freud had issued a "full and unreserved apology" stating: "To be clear, all disabled people should be paid at least the minimum wage, without exception, and I accept that it is offensive to suggest anything else."

He suggested he had been "foolish" to accept the premise of a question on the issue which had been put to him at the meeting.

But this is unlikely to stand. Labour have demanded his head and Cameron is believed to be seething that all the old nasty party attacks can now once again be levelled at his party.

And the truth is, no matter what the context was and despite the strength of Freud's apology this row, like so many before it, has taken on a political life of its own.

Miliband showed the damage the remarks will do to the government when he used them to powerful effect during question time.

Quoting from the transcript of the minister's remarks, he said: "These are not the words of someone who ought to be in charge of policy relating to the welfare of disabled people.

"Surely someone holding those views can't possibly stay in his government."

Cameron was clearly taken by surprise and insisted: "Those are not the views of the government, those are not the view of anyone in this government. The minimum wage is paid to everybody, disabled people included."

And, just as he had done at his party conference when supporting the NHS, he referred to his own late son Ivan's disability, adding: "Let me tell you, I don't need lectures from anyone about looking after disabled people."

But Miliband replied: "In the dog days of this government the Conservative party is going back to its worst instincts – unfunded tax cuts, hitting the poorest hardest, now undermining the minimum wage. The nasty party is back."

And there is the rub. Freud may believe he has been taken out of context or that his words have been given a meaning they did not contain, but it is irrelevant.

Ed Miliband
Ed Miliband had David Cameron on the back foot Reuters

The fact is to talk in such terms at all, or to be drawn into a debate in such terms shows a severe lack of political judgement and has handed Labour a massively powerful weapon to use against the Conservative party.

Charities and politicians on all sides have heard the full recording of the minister's remarks and have condemned him outright, with a number, including some Tory MPs, calling on him to resign.

And Cameron knows full well how these affairs tend to play out. A minister gaffes, is given the benefit of the doubt by his boss and holds onto his job only for the row to escalate to the point where his position becomes untenable and he either jumps or is pushed.

And throughout that extended period the government is battered by the continuing row and is distracted from other business. At the moment that other business is fighting a crucial by-election and planning for a long general election campaign.

The last thing David Cameron and the Conservative party need now is this sort of row which can be used to great campaigning effect by their enemies.

And there is nothing to suggest this particular row will not play out in exactly the same way as previous affairs.