Projects within Nationals-held electorates received the lion's share of the funding – more than $7 million – most of which was announced prior to the March election, an analysis shows.

The revelations have prompted Labor to accuse Mr Grant of "pork barrelling in the extreme" and to demand "full disclosure" of how decisions were made.

The ClubGRANTS scheme allows NSW registered clubs to claim tax breaks of up to 2.25 per cent on their poker machine profits above $1 million if they spend the equivalent amount on approved community projects.

In 2011, the government announced that a new category of funding – category 3 payments – would be introduced to support development of sport, health and community infrastructure projects.

Before the 2014-15 funding round, Mr Grant announced the maximum payment for each project would be $500,000 to "ensure greater access and reach".

But an analysis shows that of the $12.58 million in grants awarded by Mr Grant, projects in Coalition-held electorates received $11 million of the funding.

Of that, projects in Nationals-held electorates received $7 million.

Projects in the Monaro electorate – where Nationals MP and Small Business Minister John Barilaro was facing a challenge from the former MP, Labor's Steve Whan – received more than $1.3 million alone.

Labor-held electorates received just $1 million in funding for projects in Auburn and Canterbury. Lake Macquarie, held by independent Greg Piper, received $493,168.

Three electorates changed hands at the election – Campbelltown and Wyong, which Labor won from the Liberals, and Ballina, which the Greens took from the Nationals.

But each of the funding announcements for projects in these seats were made prior to the poll.

In 2013 the NSW Auditor-General questioned the transparency of how the ClubGRANTS scheme was being administered, noting the government had to date used all category 3 grants to fund election promises.

Opposition Leader Luke Foley said the breakdown of the grants showed "pork barrelling in the extreme, with Troy Grant spraying cash around like confetti to seats held by the Nationals".

"The Baird government has a fundamental issue with transparency, this time going so far as to ignore checks and balances recommended in the wake of a damning Auditor-General's report," he said.

"At a minimum, there needs to be a full disclosure of how Troy Grant came to decide how this money was distributed, followed by rigorous oversight of the allocation of these funds."

A spokesman for Mr Grant said: "There is no electorate based quota system for awarding ClubGRANTS and each application is assessed on its merits."

He said the ClubGRANTS fund committee – established to oversee the process – "recommended these applications be approved by the minister".