Leading article: Immigration belongs in the electoral mainstream

The BNP and Ukip must not be allowed to hijack this necessary debate

The Prime Minister went to Spitalfields in east London yesterday to talk about immigration.

And it should be said that he did a creditable job of handling this trickiest of subjects. It should also be said that from now on it is likely to become more difficult for mainstream politicians to talk coolly about immigration – not just for Gordon Brown, but for all major party leaders and their candidates who will soon be knocking on voters' doors – as the BNP and Ukip strive to get their messages out.

What was impressive about Mr Brown's speech was the logical and restrained tone. In almost every respect the pitch was right – something this Prime Minister has often struggled with. He sounded firm, humane and principled. There was politics, of course; how could there not be? Not least in his challenge to other parties to join him in combating "those who want to end immigration, not because of the pressures it places on our communities, but simply because they don't like migrants". A political gambit this may have been, but that does not make it wrong.

And he was right to acknowledge the need to address voters' concerns about some of the effects of immigration, just as he was right to reiterate Labour's rejection of the "cap" on numbers that is Conservative policy. Not only, he argued, would a predetermined "cap" be too inflexible, but, as a policy, it is misleading, as it could not apply to the vast majority of new migrants, including EU citizens, family members and students. It would apply only to those from non-EU countries seeking to work here – the very same group of people now subject to the recently introduced points system.

He can be accused of playing to the gallery with his message that illegal migrants "who think they can get away without ... respecting our way of life" are "not welcome". But there is, and should be, a distinction between those who play by the rules and those who do not – not just in matters of migration. It is a distinction that needs to be observed and enforced by any government, if that government is to be credible.

All that said, the speech also contained less than frank admissions that the Government's policy on migration has been flawed. The very title, "controlling migration for a fairer Britain", implicitly concedes that either control or fairness, or both, have not been adequate. The term "net migration", which is now standard in government pronouncements, rather than immigration, also needs to be watched, as it equates those leaving with those arriving – which may not be a useful comparison, especially not to those living in areas where there are "pressures" from new arrivals.

What Mr Brown described as "voters' concerns" will not be adequately addressed if there is a gap between politicians' language and the real-life experience of those voters. One potential source of misunderstanding here stems from officials' tendency, when citing figures, to focus only on those coming to the UK to work. The question of dependents is not broached, as Mr Brown in effect concedes, when he says the Conservatives' "cap" would not apply to them.

If there is to be an electoral conversation on immigration – and Ukip, but especially the BNP, must be prevented at all costs from hijacking it for their own nefarious purposes – then the mainstream parties need to show not only the same restraint, humanity and high principle that Mr Brown evinced yesterday, but rather more honesty as well.