A significant proportion of Boris Johnson’s speech formally launching his Tory leadership campaign talked up his achievements in his eight years as the mayor of London, while his more recent tenure as foreign secretary was largely glossed over. So how closely do his claims about mayoral success match the reality?

Crime

Johnson said that as mayor from 2008 to 2016 he “cut the murder rate by 50%”, that knife crime went down, and he credited a rise in police stop-and-search operations with helping reduce crime.

The reality is more mixed. The murder rate fell significantly, if not by 50% – from 155 in 2008 to a low of 94 in 2014. It did then start to rise again under Johnson, reaching 109 by 2016. The statistics for total knife offences varied over the eight years, but were only marginally lower at the end – 9,937 in total for 2008-9, against 9,738 for 2015-16.

The claim about stop-and-search curbing crime has also been contradicted. A 2016 Home Office-commissioned report on Operation Blunt 2, a Met police increase in stop-and-search that began in 2008, concluded it brought “no discernible crime-reducing effects”.

Poverty

Johnson said: “When I became mayor 11 years ago, we had four of the six poorest boroughs in the UK. When I left office after the two terms, we had none of the bottom 20.”

It is not completely clear what statistics he is referring to, as poverty can be measured in a number of ways. The standard government measure for hardship by borough is the index of multiple deprivation produced by the Ministry of Housing, Communities and Local Government.

The 2008 version of this (for England only, not the UK) does, indeed, show four London boroughs in the top 10 – Hackney, Tower Hamlets, Newham and Islington. However, the table closest to Johnson’s departure (2015 – it is not compiled every year) found that there were still four London boroughs in the top 10: Hackney, Barking and Dagenham, Tower Hamlets and Newham.

What is undeniable is that London was, in 2016, a far wealthier city overall than in 2008. However, that was a product of many factors – some not connected at all to Johnson – which brought attendant problems of inequality, both within London and compared with the rest of the UK.

Affordable homes

Johnson said he “out-built Labour with more than 100,000 affordable homes”. This is largely true: he did build more homes classed as affordable than his Labour predecessor Ken Livingstone did over eight years, even if City Hall figures placed the final tally at 94,001.

However, housing campaigners would regularly challenge Johnson over whether his definition of affordable – up to 80% of the market rent – meant they were actually much help to poorer people.

Road deaths

Johnson said he “cut road traffic fatalities by 50%”. This is not true. In 2008 there were 204 road deaths in the capital, and 116 in 2016 – a fall of 43%. This was, however, better than the 29% reduction in road deaths across the UK over the same period.

2012 Olympics

Johnson said he led London through “all the teething problems of the Olympics”, and he was in charge for the event. However, critics note that much of the planning infrastructure had been put in place by Livingstone, and that Johnson left this system largely intact. Johnson did, however, definitely preside over the controversial and hugely expensive process of finding a legacy tenant for the Olympic stadium.

2011 riots

In his speech he said he “took this city through riots”. This is the case, if you ignore the fact he initially declined to cut short a holiday to help deal with the mass civil disturbance.

Overall legacy

Johnson clearly hopes to use his time as mayor to propel himself into No 10. But many argue he achieved little in City Hall, while in the process managing to help waste £43m on a garden bridge that was never built.