In a rare intervention in local politics in the county where he served as an MP for 26 years, Lord Hague urged Communities Secretary Robert Jenrick to "make the right choice" in deciding between two radically different models of local government.
A consultation is under way as to whether the current two-tier system of local councils should be replaced by a single authority for all of North Yorkshire, with York separate, or two councils split down east/west lines.
Local organisations and residents have until early April to make their views known on the biggest changes to local government in the county since 1974.
And Rotherham-born Lord Hague, who was Tory MP for Richmond between 1989 and 2015, when he was succeeded by Rishi Sunak, said it was "a welcome opportunity to give the county a stronger voice, empower local communities, and deliver more effective and efficient local services".
In a letter to The Yorkshire Post he wrote: "Such reorganisations are always disruptive, with hard working councillors and officials at every level of government affected.
"I know first-hand from my 26 years as one of the Members of Parliament representing North Yorkshire in the House of Commons just how dedicated and passionate these individuals are, and it is vital that they are respected throughout this process.
"With the consultation launched, however, there is now a decision to be made; should these district councils be replaced by two new unitaries, separating the East and West of the county, or by a single authority stretching across all of North Yorkshire? To my mind, the best choice is the latter.
"As our country recovers from the damage of the Covid pandemic, it is more important than ever that local services, from schools to social care and everything in between, are run effectively.
"Breaking up an established county council, with a strong track record of delivering for local people, to create two new councils without the experience in providing countywide services, would generate needless challenges.
"Leaving aside the issues of transition, a single authority would also be more sustainable in the long term."
Lord Hague, who was ennobled in 2015 as Baron Hague of Richmond, said that North Yorkshire, "with its breathtaking national parks and rolling hills, is the third most sparsely populated county in England, behind Northumberland and Cumbria".
He added: "In places of such low population density, services are more expensive to deliver, making scale and critical mass essential for financial sustainability.
"It is no coincidence that Northumberland is already a single unitary authority, while Cumbria is also considering becoming one.
"North Yorkshire has for many years enjoyed highly effective local government and it is vital that this good record is maintained in the future.
"I do hope that the Secretary of State will make the right choice and deliver the single unitary authority, stretching from Richmond to Ryedale, that will protect services for local people."
Announcing the consultation last week, Communities Secretary Robert Jenrick announced that the North Yorkshire County Council and Craven district elections are to be delayed because of the controversial local government reorganisation.
Elections for all the county council’s seats were due to take place on May 6, but this will now rescheduled because of the likelihood that the authority will soon cease to exist, the Minister said in a written statement.
He said: “Elections in such circumstances risk confusing voters and would be hard to justify where members could be elected to serve shortened terms.”
Local leaders were told last summer that devolution in North Yorkshire could not happen unless the existing two-tier system of local government was abolished. Currently some services are carried out by the county council and others by seven district councils.
North Yorkshire county council has submitted a proposal for one authority covering the whole county, while district leaders want two authorities split down the A1M, with York merged into an authority with Ryedale, Selby and Scarborough.