Major challenges lie ahead for the next commissioner

The departure of the Metropolitan Police's two most senior officers in as many days could not have come at a more critical time.

Commissioner Sir Paul Stephenson and his deputy John Yates fell on their swords amid a bombardment of allegations surrounding their handling of the News of the World hacking scandal.

But they leave Britain's largest force desperately scurrying for a new leader as it prepares for some of its biggest challenges to date. The successful candidate will face five key issues:

* Policing the London 2012 Olympics, the largest logistical operation in the force's history. Sure to be the biggest headache for the new commissioner. A total of £600m has been set aside to pay for security, though ministers hope this could be cut by £125m – to cover up to 12,000 officers on duty to ensure the safety of athletes, spectators and guests. With hundreds of millions watching the Games globally, senior Met officers fear they could be the perfect spectacular for a terrorist attack.

* Rooting out corruption from a force tainted by revelations of improper relationships with journalists. Operation Elveden was launched this month to investigate allegations corrupt officers had been illegally accepting bribes from journalists in exchange for information such as phone numbers, including those of members of the Royal Family. So far a handful of policemen have been arrested but insiders warn there could be many more on the horizon.

* Ending the "freebie culture" enjoyed by senior officers. It emerged Sir Paul had accepted a £12,000 stay at Champneys luxury spa in Tring, Herts, while recuperating from tumour surgery last December. The spa employed former NOTW deputy editor Neil Wallis, who was arrested on Friday over hacking allegations, to do its PR. It also emerged that John Yates enjoyed a series of dinners with News of the World executives – even while he was supposed to be investigating allegations of illegal activity at the Sunday taboid.

* A 25 per cent reduction in net revenue expenditure over four years. Overall spending on the Met's budget for this year has already been cut by £33m and is set to fall by more as part of the Government's plans to reduce policing spend. A report released last September warned the cuts will leave the Met with a deficit of £463m by 2014.

* Buoying plunging morale among frontline officers who face cuts to pay, pensions, resources and jobs. Already 1,000 backroom jobs have gone in seven months leaving officers to fill in behind desks. Spending on police pay will fall by £217m by 2014 while Boris Johnson has vowed to have 455 fewer officers on the beat in London inside three years.

On the way up

Cressida Dick

The woman yesterday placed in charge of counter-terrorism at Scotland Yard, Assistant Commissioner Cressida Dick, 51, was at the head of the operation in which police officers shot dead Jean Charles de Menezes, the innocent Brazilian electrician they had mistaken for a fugitive suicide bomber on a Tube train in July 2005. A jury later stated that Ms Dick bore "no personal culpability". The Oxford-educated officer is highly regarded in the force and has been touted as potential future leader.

Tim Godwin

Deputy Commissioner to the Met since 2008, he stepped into Sir Paul Stephenson's shoes briefly last December, when the commissioner took leave to undergo surgery on a tumour. Known for his bravery, Mr Godwin received the Royal Humane Society Testimonial for rescuing a man from a high bridge over a railway line in 1991. After leaving the Merchant Navy in 1981, he joined Sussex police, shooting up the rankings to reach superintendent. He joined the Met in 1999 as commander.