Greer, who represents the West Scotland region at Holyrood, said: “This ridiculous company just doesn’t know when to give up, and it is bitterly disappointing that the Scottish government are helping them in their attempts to ruin this special corner of Loch Lomond.
“Extending Flamingo Land’s exclusive contract for the land means that an appeal is now all but certain, despite the overwhelming reasons for its rejection in the first place.”
The MSP added he was “incredibly frustrated” about the contract and said it “should have been terminated years ago”.
Dame Jackie Baillie, who has represented the Dumbarton constituency since 1999, said: “This was a unanimous decision of the Loch Lomond and National Park authority’s board, following a very tense meeting, during which the feelings of the community were made clear.
“I am clear that there is significant opposition to this development in the community, for a variety of reasons.”
She urged First Minister John Swinney to intervene and end the agreement.
Baillie added: “I am clear that the majority of the community do not wish this development to go ahead.”
Jim Paterson, Flamingo Land’s development director for Lomond Banks, said he hoped his company’s appeal would see “the many benefits this development would bring” being “unlocked and brought to fruition”.
He added that the final proposals for the site were adapted to “reflect more than two years of ongoing community engagement”.
Mr Paterson said the resort would add £3.9m to the local economy.
A Scottish government spokesperson said: “Scottish Ministers always consider the views of communities across many issues.
“But it is for Scottish Enterprise to look after its contractual arrangements.”