Free trips for pensioners on Waiheke Island ferries are under review because they are costing the SuperGold Card scheme too much.

Ferry trips took $2 million from the SuperGold Card's national travel budget of $18 million in their first year.

This is understood to be worrying Transport Agency officials facing a cost blowout in the free off-peak travel scheme for cardholders using public transport in Auckland and other centres.

In March, Prime Minister John Key said the Government would continue to finance the scheme - introduced in October last year - regardless of how many pensioners used it.

He said it was a successful programme, "and we will be funding the increase".

Transport Minister Steven Joyce said at the time the Government had allocated $72 million for the scheme over four years, "and at this stage we are not concerned it will exceed that".

But Grey Power's Waiheke branch president Allen Davies told the Herald last night that pensioners on the island were nervous about the future of the free trips after a senior Transport Agency official told them last week the national scheme was likely to be $12 million over budget if left unchanged.

They were told that if the Government made any changes, they would take effect from March.

Mr Davies said he called a meeting attended by more than 100 people after learning of a review to the scheme.

The agency says this was announced when the scheme started, but it began last month with no publicity other than as a brief item at the back of its October newsletter.

Mr Davies said the agency's principal planning adviser, Dave Watson, told the Waiheke meeting the full national annual budget of $18 million was used in the first 12 months.

The meeting was told that pensioners' travel on Waiheke ferry services cost $2 million in the first 12 months, and that public transport between Wellington and Wairarapa was also a big expense.

Mr Davies said Waiheke residents reportedly accounted for only 18 per cent of ferry costs, meaning a flood of Auckland pensioners had been enjoying what the island had to offer.

He said the scheme was doing wonders for the physical and mental health of older people, and was benefiting island businesses.

Mr Davies said his members were also concerned by an Auckland Regional Transport Authority proposal to end free SuperGold Card travel on ferries, buses and trains between 3pm and 6.30pm as a cost-cutting measures in response to a Government budget squeeze on public transport.

They had been told the number of trips taken by Auckland pensioners on public transport in the first year of the scheme had trebled to 4.5 million.

Transport Agency spokesman Andy Knackstedt said it had always been intended to review the scheme after its first 12 months.

He said although some transport services, such as Waiheke's, were more expensive than others, no decisions had been made on their future.