Backers of the campaign that failed to put a referendum question for a southern Maine casino on the November ballot are poised to roll the dice again.

Seven months after Maine’s secretary of state invalidated more than 55,000 of the group’s petition signatures, a pro-casino campaign is stockpiling cash and appears to be gearing up for a drive to gather enough signatures to secure a spot on the 2017 ballot.

The sister of international casino developer Shawn Scott donated $300,000 to Horseracing Jobs Fairness – the group behind the York County casino campaign – on Sept. 28, bringing her total contributions to $3.5 million. Lisa Scott’s latest donation leaves Horseracing Jobs Fairness with nearly $1 million in the bank, according to campaign finance reports filed this week.

The campaign already has gathered more than 35,000 valid signatures from Maine voters – roughly 57 percent of the total needed to qualify for the ballot.

Representatives for the campaign or petition circulators did not return calls for comment Wednesday. But there has been talk recently on internet sites frequented by professional signature-gatherers about a renewed push to collect the remaining signatures in Maine.

Also, the campaign filed paperwork this week providing the Secretary of State’s Office with the names of individuals who have been hired to circulate petitions in Maine.

“That would indicate that there might be some intent to renew their effort,” said Kristen Muszynski, spokeswoman for Secretary of State Matt Dunlap’s office.

An online ad posted on Craigslist seeks workers across the state to gather signatures for an unnamed campaign. While there are currently six campaigns authorized to gather signatures for potential ballot questions, the ad first posted on Sept. 28, the same day as Scott’s $300,000 contribution to Horseracing Jobs Fairness.

“We will have work for the next 5-6 weeks,” reads the ad offering petitioners $120 per eight-hour day. “Pay is twice per week. This is an independent contractor position.”

The casino campaign has until June 8 to gather the requisite number of signatures. If Horseracing Jobs Fairness is indeed relaunching its signature-gathering effort, it would be the latest twist in a strange, high-priced and controversial campaign to bring gambling to the southern end of the state.

The state already has two gambling establishments: Hollywood Casino in Bangor and Oxford Casino in western Maine. A casino in York County, however, could more readily draw gamblers from population centers in neighboring New Hampshire and Massachusetts.

The proposed ballot measure was written in a way that it would allow just one person – Las Vegas entrepreneur Shawn Scott – to bring slot machines or a casino to York County. Scott successfully won voter approval for Maine’s first gambling facility in 2003, but ultimately sold the rights to build what is now Hollywood Casino to another firm, reportedly netting himself $51 million.

Lisa Scott, a Miami resident described as a self-employed real estate developer, has contributed all $3.5 million reported by the campaign so far, but the significant spending did not lead to a spot on this November’s ballot.

In March, Dunlap invalidated 55,776 of the 91,294 petition signatures submitted by the campaign, because the signers were not registered voters, signatures were duplicates or there were authenticity questions about the notary’s signature, among other reasons. That left just 35,518 valid signatures, well short of the 61,123 needed to qualify.

For weeks, Dunlap’s office and local town clerks and the media had received complaints about sloppy, illegal or deceitful practices by circulators gathering signatures on street corners, outside stores or on city sidewalks. Those circulators – many of them full-time signature-gatherers who work on campaigns nationwide – were reportedly being offered up to $10 a signature plus free housing and transportation as organizers sprinted to meet the cutoff for submitting petitions to state elections officials.

The high-profile campaign shed light on the growing national industry surrounding ballot initiatives in which professional petitioners travel around the country to solicit for signatures.

Some of the petition circulators in Maine have complained that they were never paid, a claim complicated by the state’s invalidation of more than 55,000 signatures. The fact that Horseracing Jobs Fairness had $963,493 in the bank as of Sept. 30 is likely to renew calls for payment among those who feel they were stiffed during the last signature drive.