"I don't think people should do kissing in the park, do you Mummy? I mean, it's all right holding hands and things - if you really love someone - but kissing? With people watching and everything!""Well, let's not watch, then," I suggest. To their credit, the couple do their best to look impressed as Con performs the not very complicated manoeuvre of skating-with-hands-on-knees."No worries, mate," calls the nice young man, when I arrive to tow Con away. It is that wondrous time of year again when summer is suddenly upon us. The young London male has shrugged off his shirt and tied it round his waist and, in hormonally determined response, girls are knotting their T-shirts above their midriffs and kicking up their heels in the new grass. On a park bench, a couple of Australian Goths, coitally entwined, are pulled back from the point of no return by my son Conor, on roller-blades, arriving in their midst unannounced and somewhat out of control. "Sorry," pants Con, to the no-less-breathless couple, "I'm a good skater, but I'm not very good at stopping My name's Conor," he says, remembering his manners "D'you want to see a roller-blading trick?". Regent's Park.

Mr Blair's account of what migrant workers have contributed to Britain, and what they still have to offer, made a refreshing change from the moral cowardice, evasion and "tough" posturing we have seen all too often in the past. Now his ministers must follow his lead: stop pandering to their enemies and start defending immigration with equal boldness and resolve.. To appease them, Mr Blair announced that restrictions will be introduced to prevent jobless EU immigrants being given housing benefit for two years, but this is an irrelevant measure. As the Prime Minister repeatedly pointed out himself yesterday, most immigrants come to work, not to sign on.On the whole, yesterday's speech stood out for the right reasons. He talked about the contributions immigrants have made in fields such as sport and music, and emphasised the cultural boost they have provided over centuries.

We have avoided, on the whole, ghettos, segregation and other injustices that have soured race relations in other nations.But amid such positive talk, it was disappointing to hear the Prime Minister returning to the old canard that immigrants cheat our welfare system - a line from the speech which No 10 shamefully leaked before it was delivered to its friends in sections of the press. He was also surely right to stress just how well Britain has accommodated immigrants. Many are well-educated, skilled and eager to utilise their talents to the benefit of their host nation.Mr Blair set out the economic case for immigration impressively; he also discussed the social advantages for Britain. Mr Blair rightly stressed the benefits of workers from these countries exercising their right to come to Britain.

The Prime Minister was also right to point out that many thousands of native-born Britons decide to work abroad, buy property overseas, or emigrate each year. Forget the sorry row about whistle-blowers and Bulgarian visas that has dominated the news agenda in recent weeks; Britain desperately needs these workers. Around 100,000 east and central Europeans are already here, either working or studying, and our economy is well capable of accommodating those extra ones who will come and work. The fact that they tend to enjoy the rather grand title of "ex-pat" rather than "economic migrant" reveals the levels of British hypocrisy.Of course, the timing of the Prime Minister's speech owes much to that historic moment on Saturday when 10 new countries will officially accede to the European Union. We also have lower levels of foreign-born nationals as a proportion of our population than either France or Germany. Rather than being inundated, Britain is lagging behind the rest of the world.