Fax are currently enjoying their best season for years, with Friday night's narrow loss at Salford seeing them slip to second in National League One, just one point behind the Reds.
They are also one of 19 clubs gunning for a top flight berth under the sport's new franchise set up, which will see Super League expand to 14 teams from next year.
The big spenders of the National Leagues - Widnes, Salford and Celtic Crusaders - remain the favourites for the two extra places, which will be announced on July 22, with a newspaper report in South Wales over the weekend claiming it had learned that Celtic were a shoo-in.
Clay is refusing to throw the towel in on Fax's application, although with two home games - the televised date with Leigh next Thursday and the return bout with fellow title contenders Widnes nine days later - on the agenda before D-Day, he accepted attendance levels at the Shay are not helping the club's cause.
Fax's last three home games - against modestly trio Batley, Dewsbury and Whitehaven - all attracted around 2,000 fans, figures which represent a significant percentage increase on recent seasons, but are still some way short of their main rivals.
"Attendances are definitely on the up and we are very pleased with that," admitted Clay.
"We are playing some tremendous rugby league this season, and that's been reflected in the number of people coming through the gates, especially for the Melbourne Storm and Huddersfield matches.
"But when you look at clubs like Widnes and Celtic, who have had attendances of 8,000 and 6,000 for league matches, we need to start hitting some bigger numbers pretty quickly.
"The next two home games represent a tremendous opportunity to show the RFL that the area is capable of sustaining a Super League side before the final decision on licences is made.
"We can improve the team, we can make sure we are playing entertaining, winning rugby, but if people are not coming through the turnstiles in sufficient numbers the bottom line is that that is going to hamper our aspirations.
"I would hate to sit down on July 23 and think we ended up missing out on a licence because people thought the public of Calderdale weren't interested."