The UK government’s plan for changes to tax relief risk a pensions “implosion” that could undermine the foundations of the country’s tax system.

Ruston Smith, outgoing chairman of the National Association of Pension Funds (NAPF), argued his organisation’s role was to act as a “social conscience and savers’ champion” and cautioned the government against implementing radical changes to the tax system.

Opening the NAPF’s annual conference in Manchester, Smith, also group pensions director at supermarket chain Tesco, said change should not be confused with improvement.

He argued that it was the NAPF’s role to challenge government.

“If we stood and watched as changes were made to the industry, we’d end up with higher DB deficits, regulation that doesn’t work and reforms that can’t be implemented,” he said.

“If we stand and watch, short-term fixes will damage long-term gains.”

Smith reserved his harshest criticism for changes to pension taxation put out to consultation by the UK Treasury in July, coming in the wake of an overhaul that saw savers allowed to draw down their pensions pots from 55.

“The government says it wants to strengthen the incentive to save, but it’s ulterior motive is to increase short-term tax revenue,” he said.

“If the government gets its way on reforms to pensions tax relief, we could see the recent wave of change – the pensions revolution – becoming a pensions implosion.

“[It’s] tax change that could literally dig up and smash the foundations set to create a society of lifetime savers, putting pressure back on our ageing society.”

The consultation launched over the summer proposed a shift from the Exempt-Exempt-Taxed model to a Taxed-Exempt-Exempt approach.

Stewart Hosie, pensions partner at KPMG, previously argued that the government would be better placed to determine whether the current tax system provided value for money, and delivered on its own policy goals.