Now GP registration lead at the CQC, he admits the process is a 'headache' for GPs reeling from sweeping NHS reforms, budget cuts and revalidation.
He accepts too that GPs have every right to question the CQC's ability to deal with them fairly and competently. The CQC exited 2011 amid calls for the heads of its senior executives after the National Audit Office (NAO) warned it did not offer value for money, and following a series of high-profile failings.
PCTs have done little to enhance GPs' enthusiasm. Professor Haslam blames PCTs for creating myths about registration - that carpets will be stripped out, dress codes imposed, waiting room toys destroyed or premises shut down because they lack disabled access. 'There's no truth in that at all,' he says.
One factor the NAO blamed in part for the CQC's struggles was its rapid evolution. It formed in 2009 from a merger of three separate regulators.
Professor Haslam says: 'We were given a massive task, assessing acute trusts, mental health, social care and dentistry. We recognised if we carried on at that speed we would not be able to do as good a job for general practice as it deserves.'
A 12-month delay in GP registration to April 2013 has allowed the CQC vital breathing space. Forms and other elements of GP registration have been simplified and clarified since pilots in 2011, and continue to be through a reference group the CQC is encouraging GPs' practices to join.
Lessons have also been learned from registering dentists. Professor Haslam says: 'It'll be pared as close to the bone as we can. The aim is to get rid of anything that isn't essential. There was an awful lot of unnecessary stuff for dentists particularly - GPs will have a lot of friends who are dentists who have horror stories - but the message is it may have been true, but it won't be true.'
Professor Haslam says: 'Most partnerships will already be doing almost everything we want. They will have in their practices ways of making sure medicines are handled safely, that safeguarding is dealt with properly. It's just part of running a business.
'Practices will declare they are or are not compliant, and they need to be prepared for us to say: "Prove it.".'
Even practices that do not comply fully will be able to register - they simply declare non-compliance and set out how they are dealing with the problem.
Professor Haslam explains: 'If a practice has no disability access and says we will go and visit patients affected, as far as we are concerned they have addressed that problem.'
There is a 'tiny rump' of practices that will struggle more fundamentally, however.
'Pretty well every doctor knows of practices they would not be happy for their family to be registered at,' Professor Haslam says. Several generations of NHS trusts have failed to resolve this. But he says: 'We hope the CQC will be in a position to sort that out.'
Only practices where 'massive concerns' emerge will face unannounced inspections, Professor Haslam says. Others will face only planned visits to limit disruption. How these will work is still being developed, with pilots in May 2012.
Fees similar to dentists
How much it will cost GPs will only become clear after a consultation this summer, but fees could be similar to the £1,000 a year that dentists pay. The system could reflect how many partners practices have, or their turnover, but will be tiered to reflect practices' size.
Practices face fines if they miss the April 2013 deadline for CQC registration, but will be able to begin registering online from this summer. Some will formally register earlier than others to help the CQC cope. Practices will be able to choose on a first-come first-served basis to register in any of a series of 28-day windows starting from September.
Professor Haslam says roadshows last year convinced many GPs that registration with the CQC will not be as bad as they had thought, but he admits far more work remains.
But he is adamant he will work hard to limit its impact. 'I've spent a lifetime as a GP and the last thing I want is my colleagues to spend their lives doing stuff that is unnecessary.'