As old favourites like immigration and NHS pay resurfaced in public debate, a conversation I overheard in a Berkshire pub years ago popped up again this week.

The two middle-aged pub customers were banging on about immigrants, of whom few are visible in rural Berkshire. I was tempted to say: 'Who's going to look after you in your old age, chum? If they're your kids in the family room you've left it a bit late to have them and you didn't have enough.'

My answer is not the whole answer, of course. These are complex issues, harder to balance socially or economically than is suggested by frequent official assertions that 'society benefits from immigration'.

Indeed it does. This week's Sunday Times alleged mistreatment of patients in a Midlands care home. Many of the carers being paid£6.35 an hour came from overseas. They are both good and bad, like us all.

That is true of most big city hospitals. It has been a cliche for 50 years that the NHS cannot do without the foreign staff Enoch Powell as health minister recruited in large numbers. But The Sunday Times reported a South African doctor, banned abroad, finally being suspended here. Some complaints about nursing standards also attract the tempting label 'foreign'.

There is a flip side. Tucked away in an NHS staff survey published last week by NHS trade unions - to highlight morale and recruitment problems for 2008-09 pay negotiation purposes - is a table of 'racist jokes, banter, insults' etc suffered at work.

Of this 9.1 per cent of all staff got abuse from patients or carers; 6.9 per cent from staff; and 2.5 per cent from management. Men suffered significantly more than women, who suffered worse in the sexual harassment table. Here hassle from patients/carers topped 13.8 per cent.

NHS promotion for ethnic minorities is also a recurring controversy. No surprise there either. But in the context of pay it is part of the debate we have long shied away from: allowing outsiders from the developing world to work in Britain - wider Europe too - has sometimes been a way of not paying the locals more and not investing more capital equipment and training in the workforce.

Sound familiar? Yes, but that is not the whole story either. Some unskilled teenagers or people on invalidity benefit may be kept out of an NHS job by a nice Nigerian or a pushy Pole. Others just will not do these jobs. There is even a parallel debate among those city high-fliers whose huge bonuses so annoy the NHS unions: do foreign bankers here deny jobs to London bankers or raise their game?

At least we do not have to worry about rich immigrants bringing in hepatitis B or TB, although we should worry about them depriving their own country of their skills, doctors and nurses being a sensitive case which we never quite get right.

The last time ministers promised to scale down overseas recruitment of nurses the Royal College of Nursing accused them of 'scapegoating' foreigners. Even Dr Andrew Murrison MP, a Tory health spokesman, complained that the policy was 'shortsighted' because so many nurses are set to retire.

MPs tend towards the cowardly in this debate, although it is not hard to see why. Blair-Brown embraced a lax immigration policy to promote labour market 'flexibility' - it eases pressure for higher wages - and in recognition of genuine asylum pressures and globalisation.

Tories who called for a managed policy were dismissed as not-so-closet racists by Labour, although ministers are belatedly trying to impose their own points system.

Sensible Labour MPs know some Labour voters are losing out and that the British National Party is hovering. So a debate we should have, one in which anti-immigration bodies like Migration Watch UK and those in favour like the Institute for Public Policy Research both get a proper hearing.

Last week Conservative leader David Cameron managed to raise the key issue of overall numbers by sensibly putting it into the wider demographic context: an ageing population, plus pressure on local schools, councils and NHS service.

He forced out a Tory candidate for saying 'Enoch was right'. Surely, we're past the Enoch stage?