It is two years since Boris Johnson stormed to a general election victory on the back of a promise to "get Brexit done".

Voters had rewarded him with a mandate to negotiate the UK's exit from the European Union. But as most Prime Ministers discover, winning office is one thing; delivering on promises made during a general election campaign is another.

Our political editor Paul Francis assesses the highs and lows of his time in Downing Street as the political storm rages over Downing Street parties taking place during lockdown.

Standing on the steps of Downing Street in December 2019, Boris Johnson could not have been more ebullient after scoring a decisive victory in a general election dominated largely by Brexit.

His handsome majority led him to repeat one of the campaign’s key slogans: a promise to unite the country and level up.

In Kent the party swept up all but one of the parliamentary seats, with most MPs seeing their majorities increase beyond expectations.

It was an unusual election: the issue of Brexit and the failure of his predecessor Theresa May to come up with a deal that would satisfy voters led some to believe that the Conservatives could be vulnerable.

As it happened the result proved just the opposite, with the party securing an 80-seat majority, cementing Johnson’s reputation as an election winner.

It also gave him a solid mandate on which he could secure a Brexit deal with the EU.

Under his leadership, the government negotiated a trade deal which was seen as an acceptable compromise, with the exception of hard-line Bexiteers.

But the unpredictable nature of politics could not have been illustrated more vividly than by the outbreak of the coronavirus pandemic.

The country was plunged into a series of lockdowns, with far-reaching ramifications for the economy as thousands were furloughed.

There were devastating consequences for thousands of families who suffered the losses of loved ones and, as a result of restrictions, were unable to be with them when needed most.

The Prime Minister faced criticism of his judgements over restrictions, with many saying he acted too late to implement them, leading to unnecessary deaths.

The government's warning that the virus did not discriminate proved unerringly accurate when in April 2020, the Prime Minister succumbed to Covid-19 and was admitted to intensive care, eventually recovering but admitting that it had been touch and go.

With the delivery of a vaccine, the spread of the infection was stemmed and the country inched back to a degree of normality.

The first vaccine was administered in early December 2020 and marked a significant step in the fight against the virus.

It also marked a point at which the Prime Minister saw a lift in in the poll ratings - dubbed the jab bounce.

That was before another period marked by indecisiveness on the part of the PM.

Announcing that he was easing lockdown measures in December, he told a press conference: “I want to be clear, we don’t want to ban Christmas. And I think that would be frankly inhuman and against the instincts of many people in this country.”

But a few days later families were told they could not mix as the government effectively cancelled Christmas with a third lockdown and another period of restrictions implemented.

The PM’s critics included a number of his own MPs, among them South Thanet's Craig Mackinlay, a member of the Coronavirus Recovery Group of backbenchers.

Their concerns revolved around the issue of civil liberties and the right to personal choice; along with reservations about the impact of measures they argued were disproportionate.

As the Brexit deadline edged closer, Kent experienced at first hand how vulnerable the UK might be outside the EU.

Contingency plans to deal with the possibility of the county being gridlocked were activated in December 2020 - ironically not because of Brexit but because of Covid.

The French authorities imposed a ban on freight lorries crossing through the Channel Tunnel amid fears of a new virulent strain of the virus.

Thousands of lorries were stranded, forced to holding sites, including Manston Airport, while the government tried to thrash out a deal to get things moving.

For Europhiles, the event illustrated the vulnerability of the UK’s borders and its lack of clout.

But when the time came for Brexit Day on January 31, 2020, it passed the Commons with scarcely a murmur.

Aside from Brexit and Covid, there has been the ongoing issue of record numbers of asylum seekers crossing the Channel and landing on Kent's shores in often fragile looking dinghies.

The constant stream over the summer has seen record numbers of arrivals and the UK has yet to find a way to resolve the issue.

The Prime Minister has claimed new legislation will give the UK stronger sanctions and fines for the criminal gangs who trade in smuggling.

The tragic death of 27 people in a crammed dinghy which appeared to have malfunctioned was an all too vivid a reminder of the human cost.

His critics on this front come from separate wings of the party: Those who see the UK's inability to act unilaterally as the cost of leaving the EU and those who contend that the government should be adopting a much firmer stance.

There has been a cautious reaction to another key policy promise, in the form of a plan to increase National Insurance contributions to help fund adult social care costs.

This also drew criticism from not just the opposition parties but from his own backbenchers concerned that the application of a cap on costs would have a disproportionately adverse impact on poorer families.

Away from the policy backdrop, he has seen his personal poll rating slip into negative territory.

There have been questions about the refurbishment of the Downing Street flat, which has led to the Conservative Party being fined £18,000 as well as questions about a holiday in Mustique.

Revelations about MPs and second jobs saw an ill-conceived and damaging attempt to spare the minister Owen Paterson from serving a 30-day suspension from Parliament for failing to disclose financial interests.

'In the same way that Christmas baubles lose their lustre, some of the shine has come off the Prime Minister...'

The public outrage was on a scale not seen since the expenses scandal and further damaged his credibility.

His rambling Peppa Pig speech to business chiefs led to suggestions that the pressure was getting to him.

And then there is the on-going row after at least one party took place at Downing Street during lockdown.

On the political barometer, the political weather has led to storm clouds gathering ominously over Downing Street.

As more information comes to light, the explanations provided by the PM seem increasingly threadbare, with the logically perverse assertion that all the rules and guidance had been observed at all times for an event that did not take place.

If the inquiries underway elicit information that suggests he has not been entirely straight, could he be out of a job?

At least one Kent MP believes that could be the dramatic outcome.

Thanet North MP Sir Roger Gale - not his biggest fan, admittedly - says that if Johnson is shown to have misled Parliament then “the game would be up”.

It seems far-fetched but then the twists and turns of politics often catch you by surprise.

Whatever else he might achieve and has achieved would be overshadowed by becoming the first leader of a country whose demise was precipitated by a festive scandal involving a Christmas party.

Not the epitaph he would choose. But in the same way that Christmas baubles lose their lustre, some of the shine has come off the Prime Minister.