Yorkshire First is holding a party conference in York on Saturday 7 November.
The conference - the party's first since being established in 2014 - will be held in the city's Clements Hall.
As some Yorkshire council leaders meet the Communities Secretary Greg Clark today, leader of Yorkshire First, Richard Carter, said:
"We are delighted that devolution is on the Government's agenda. However, what has been offered so far is an insult to the people of Yorkshire.
"A backroom deal between George Osborne and local council leaders has produced an arrangement which is limited in scope, divisive and undemocratic. Frankly what's on offer is feeble.
"We have always said we need a first class devolution settlement based on real evidence and which clearly supports the needs and aspirations of our communities across Yorkshire. We have been calling for a Yorkshire Conversation for over 18 months which we believe can help achieve this. Political leaders could lead that conversation but it must be one where grassroots voices are heard."
On the matter of Yorkshire First, Richard Carter went on:
"We are slowly building a movement to challenge both Westminster and local elites. We have recruited those with political experience such as the Mayor of Market Weighton and those with no previous political background. In the two recent Council by-elections, one in Barnsley the other in Wakefield, we averaged 8.5%. Both were wards where we had not stood before.
"We are also building Yorkshire First from bottom up. Local groups are springing up all over the county and making a direct input into how a devolved Yorkshire would look. Those groups are selecting candidates for next year's local elections.
"However, political success is not just about winning at the ballot box; for us it's also about influencing government policy. We have a fierce ambition to continue to force the political debate as we have done over the past 18 months. There is still a lot to be done to create a Yorkshire which works for all its people and Yorkshire First will continue to be part of that work."
In the two recent Council by-elections, one in Barnsley (Dearne North ward) and one in Wakefield (Pontefract North ward) Yorkshire First averaged 8.5%, beating the Conservatives in the first and the Liberal Democrats in the second.