The government is "long on public relations and rhetoric" about boosting "left behind" parts of England but has yet to deliver, a former minister says.
Lord O'Neill said a long-awaited plan to shake-up local government appeared to have been delayed again.
It was a "worrying" sign ministers were not "capable" of dealing with anything but the coronavirus pandemic, he added.
The government said it was still considering options and the proposals would be published "in due course".
But ministers remained committed to "levelling up" power and wealth across the country, a spokesperson said.
Boris Johnson has promised the biggest reform of local government in a generation, as part of a plan to close the North/South divide and boost parts of England that voted Tory for the first time in the general election last year.
The plans are likely to include the creation of more unitary authorities, ending the overlapping system of county and district councils in many areas, and more elected "metro mayors" like those in Greater Manchester and Tees Valley.
But the Financial Times reported that a white paper on devolution and local recovery, due to be published this month, had been put back to next year.
Lord O'Neill, who is vice-chairman of the Northern Powerhouse partnership - set up by former chancellor George Osborne to make the north of England more prosperous - said the delay was a cause for concern.
He told BBC Somerset's political reporter Ruth Bradley: "It's consistent with a worrying, reoccurring sign that this government is not really capable of dealing with anything other than the immediacy of Covid-19, which I'm sure some people would have sympathy for.
"But when you start by talking repeatedly about levelling up, and with a prime minister visiting, deliberately, left-behind places to do so, it doesn't really create a very good impression, especially because the left-behind places have almost definitely suffered most from Covid-19.
"This is a mysterious government. It strikes me that it's very long on public relations and rhetoric, but not really figured out how to focus on delivering anything, and it gets more and more disappointing by the week."
The former Treasury minister added: "I got very excited when this government came to power and started talking about levelling up and devolution.
"And it's crucially important for a more balanced economic future of the UK and I believe it's vital. But unfortunately for various reasons this government repeatedly seems to keep on finding a reason to either delay it or just not actually pursue the actions that its words suggest they are going to."
The County Councils Network, which represents 36 mainly Conservative-controlled local authorities across England, said: "Suggestions that the white paper is to be delayed is disappointing.
"When it is ultimately released, it must follow through on the government's commitment to extend devolution in England and set out a clear blueprint of how this can be achieved in county areas.
"Given the financial and economic shocks of coronavirus, it is imperative that county authorities have as much resource and powers at their disposal to address the issues in their left-behind communities."
A spokesperson for the Ministry of Housing, Communities and Local Government said: "We have set out a clear commitment to level up all areas of the country by empowering our regions through devolving money, resources and control away from Westminster.
"We are considering a range of options and will set out our detailed plans in the white paper that will be published in due course."