Based on a US concept, nurses on the programme visit vulnerable first-time parents in their homes, from early pregnancy until the child is two-years-old.
Ten sites across the country have been piloting the government-backed project since 2007.
The publication of the final evaluation of the pilots is expected this spring, but concerns have already been raised about the future sustainability of the programme, with one of the original 10 pilots due to end in June.
Jacqueline Barnes, professor of psychology at Birkbeck University of London and lead investigator for the project, said: "There has been a varied response from commissioners. Some are very behind it, but others are on a tight budget and can't justify the spend."
Barnes said some commissioners are unsupportive of the scheme because they feel it puts an unbalanced focus on vulnerable parents and risks overlooking problems known to affect all families, such as post-natal depression and domestic abuse.
She added: "The recession has hit at a time when the project really needs money. The nurses are extremely worried about it being cut as they are only contracted one year at a time. It's unstable because it isn't embedded in the system so it's the easiest thing to cut."
Trade union Unite's lead officer for nursing Barry Brown shared Barnes' concerns: "We are aware that it seems to be an easy target. The funding is secured for this year so the squeeze will happen next year. It's a real cause of concern for nurses."
The last evaluation of the pilots, published in September 2008, showed some positive results, including that the programme has contributed to an increase in breastfeeding.
Barnes added that cutting funding for the programme - which costs about £3,000 per client a year — was shortsighted and would undermine the principles of early intervention: "The project is cost-saving in the long term. If you compare it with the cost per head of a looked-after child, it's very cheap."
