Economic support grants to be announced by the state government this week will include funds not used in earlier relief schemes as well as new money, while more than $1 billion previously set aside is yet to be spent.

Internal emails between Treasury staff last year, obtained under freedom of information laws, reveal $310 million was reserved for hospitality and retail businesses in October.

The money was approved by the government for the Summer Holiday Stock Guarantee, to award grants of up to $10,000 or $20,000 to compensate for lost perishable stock if a lockdown occurred between December 1 and January 31.

“Under the best-case scenario, where no further lockdown eventuates, the scheme would not be drawn on,” an email on October 12 said. “The potential exposure for a statewide lockdown is, however, estimated at $310 million,” an email on October 12 states.”

As no stay-at-home orders or business closures were enforced in the summer period, the money was never required, freeing it up to be used in other support packages.

Other programs yet to be fully realised include the commercial landlord hardship fund, the small business fees and charges rebate scheme, and the $25 Dine and Discover vouchers.

Consumers are also yet to redeem about $400 million in Dine and Discover vouchers, which expire on June 30. A further $376 million remains in government coffers from the small business fees and charges rebate program. Money under those programs will not be reallocated.

Together the underspend of COVID relief programs totals $1.12 billion.

A NSW Treasury spokesman said the government had committed more than $45 billion in economic and social recovery measures since the start of the pandemic, with many programs experiencing underspend or overspend.