The UK’s £2bn (€2.2bn) industry-wide scheme for plumbers has proposed to close to future benefit accrual.The Plumbing & Mechanical Services Industry Pension Scheme launched an employer consultation yesterday, seeking to gather responses by 16 September.The trustee board of the scheme – which caters for more than 35,000 people and 360 businesses – said that, while it had sufficient assets to pay benefits, low expected returns in future could cause contributions to rise “significantly”.Employers’ contributions would increase from 10.6% of salary under the scheme’s “basic scale” to 19.6%, while employees’ payments would rise from 5.3% to 9.8% of salary. Many companies in the plumbing scheme are small businesses, meaning contribution increases could quickly become unaffordable.Under the proposal put to employers by the trustee board, the scheme would close to future accrual “no sooner than 30 June 2019”. The trustees said they had considered other options, including adjusting the balance of contributions or reducing benefits, but rejected these as either unaffordable or resulting in insufficient pensions.The board also decided against introducing a defined contribution (DC) section.“New defined contribution arrangements can be expensive to set up and run,” the trustees said. “This option was not chosen because following investigation it was not considered financially viable for the scheme to operate [a DC section].”Instead, the board indicated that individual employers should make their own arrangements to ensure they comply with auto-enrolment requirements.Any changes must be agreed between the trustees, industry associations and unions before being finalised.The Plumbing & Mechanical Services Industry Pension Scheme has been acting to reduce costs for some time. In September 2017 it completed a £560m insurance buy-in with Legal & General, securing payments for pensioner members.Earlier this year, the UK government relaxed rules for multi-employer schemes to help sponsoring employers avoid crippling payments when they no longer have any staff participating in the arrangement. It followed pressure from politicians representing small plumbing businesses that faced unaffordable payments to settle so-called “section 75 debt”.