A slowness in implementing changes following the Grenfell tragedy and a lack of training for reacting to terror attacks are among the criticisms of the fire service in a new report.

London's firefighters are attending a disproportionately high number of false alarms, while some fire engine drivers have not received refresher training for 20 years, Her Majesty's Inspectorate of Constabulary and Fire and Rescue Services (HMICFRS) has said.

London Fire Brigade (LFB) was one of three services across England to require improvement in three key areas, following a review of a third of the country's services.

The LFB's assessment identified areas of strength, such as being well-resourced with staff and exceeding its own standards on response times.

But the report was scathing of its current effectiveness for protecting the public through fire regulation, how it uses its resources, and said it is "worryingly inadequate" at "getting the right people with the right skills".

Matt Parr, HM Inspector of Fire and Rescue Services, said: "This is a disappointing report: there are too many areas where the London Fire Brigade needs to make improvements."

He added: "Many of its projects are wasteful, projects get started and stalled.

"The organisation as a whole is slow to learn.

"We are absolutely not criticising every firefighter in London - there are lots of people who are very dedicated.

"But what it doesn't leave you with is the impression that the organisation is well-run and where value for money is top of their agenda."

LFB commissioner Dany Cotton, who will retire at the end of the month, had seen the report before she announced the decision to bring her resignation forward from April 2020, Mr Parr said.

The report said LFB "has clearly learned lessons from the Grenfell Tower incident".

However, it "has been slow to implement the changes needed, which is typical of the brigade's approach to organisational change", it added.

The report also said LFB's training and development plans "aren't realistic and can't assure the public that the brigade gives adequate priority to risk-critical training".

It found some fire engine drivers had not received refresher training for up to 20 years, despite national guidance recommending this takes place every five years.

Elsewhere, the inspectorate found most of the senior commanders said they had not had incident training "for several years", while there is no systematic training programme for firefighters tasked with responding to terror attacks in the capital - with many frontline officers saying they do not have suitable personal protective equipment and "lack the confidence" to respond.

The report found LFB had not done enough to "reduce the burden of false alarms", in that it was only managing to weed out 3.7% of automatic fire alarm requests for assistance - much lower than the average of 30% across England.

Mr Parr described LFB response times - some six minutes and 39 seconds on average as of the year 2017-18 - as "excellent", but said around 48% of its call-outs were false alarms.

The watchdog said senior LFB commanders rarely exercised "operational discretion" to deviate from brigade policy.

The report did not make explicit reference to the brigade's much-condemned "stay put" policy, when Grenfell residents were told to remain in their flats by firefighters and 999 operators for nearly two hours after the blaze broke out in the middle of the night in June 2017.

Inquiry chairman Sir Martin Moore-Bick subsequently identified how more lives could have been saved had the policy been abandoned sooner.

The HMICFRS report found there were just six reported examples of operational discretion in two years, something described as "strikingly low", and based on the fact that incident commanders said they "aren't confident that the brigade would support them in using operational discretion".

Andy Roe, who will replace Ms Cotton as London Fire Commissioner from January, said: "I recognise that what's been highlighted in the report isn't good enough and as the new commissioner I am committed to making the necessary improvements when I take on the position in January.

"We are already delivering some of the key improvements they have highlighted and doing everything we can to provide the best possible service to the people of London and keep them safe."

Matt Wrack, Fire Brigades Union general secretary, described the latest reports as "a complete indictment of the government's dangerous complacency over the risk of fire, flooding, and other hazardous incidents".

He added: "Austerity has ravaged our fire and rescue service, leaving residents in many areas at risk.

"With no national standards and no national infrastructure coordinating fire and rescue service policy, residents inevitably face a postcode lottery of fire safety.

"While fire service bosses must be responsible for any failings, so too should the politicians who have starved them of funding, resources and boots on the ground. Our service is collapsing - it's plainly unsustainable."