It is officially the launch of the Conservative Party’s general election campaign. I watch as exhausted security guards wave in Tory members filing towards the Excel Centre in the shadow of derelict shipping buildings and super yachts.
Past the sniffer dogs and blacked-out Range Rovers, I am greeted by a cheery Tory press officer equipped with an umbrella - clearly learning his lesson from Rishi Sunak’s washout outside Downing Street.
Mr Sunak’s first campaign rally has clearly been organised at late notice - with some Tory MPs reportedly feeling cajoled into attending.
Past airport-style security we are led into the press room - with frustrated journalists pacing like tigers after being denied access to the Tory activists flocking in with bright new ‘Vote Conservative’ signs pressed into their hands.
Meanwhile, Sky’s political anchor Darren McCaffrey is already complaining to a media handler, who explains there is not enough room for their camera in the cramped room hired for the prime minister’s speech.
The anchor promises to make a “huge deal” about it and he later does - ending up being “forcibly ejected” by security live on camera during the launch.
After a 30-minute wait we pile into a sterile, sweltering room where dozens of Tory members holding the latest slogan from the latest election are assembled like a choir about to burst into You Can’t Always Get What You Want.
The cleverly chosen smaller conference room appears fit to bursting for the cameras, with only around 80 activists there.
Some bop their heads to the inoffensive yet interminable hold music being played repeatedly over the tannoy as they wait for their leader to arrive.
The hype builds as Michael Gove comes in first to rapturous applause, followed by chancellor Jeremy Hunt and foreign secretary Lord David Cameron.
But Mr Sunak’s opening host of choice is home secretary James Cleverly - I suspect, the funniest Conservative frontbencher he could find at such short notice.
His routine lays into Labour leader Sir Keir Starmer for supporting Jeremy Corbyn twice, and hails Mr Sunak’s mastery over plummeting inflation rates. All the familiar Tory notes are played, and the crowd laughs along loudly.
And then the main event begins, and huge cheers greet the man of the moment Mr Sunak. By this time he has ditched his sodden blazer for a classic Obama-esque white shirt - yet his trousers still appear to be soaking.
Mr Cleverly clearly doesn’t care and gives him an enormous bear hug of support.
The prime minister doesn’t speak to the crowd of worshippers but directly into the autocue, telling supporters: “We are going to fight every day for our values and our vision, and the British people are going to show Labour that they don’t take too kindly to being taken for granted.”
In personal attacks on Sir Keir Starmer, he adds: “If he was happy to abandon all the promises that he made to become Labour leader once he got the job, how can you know that he would do exactly the same thing if he were to become prime minister?
“If he doesn’t have the conviction to stick to anything he says, if he doesn’t have the courage to tell people what he wants to do, and if he doesn’t have a plan, how can he possibly be trusted to lead our country, especially at this the most uncertain of times?”
And then it’s all kisses and hugs with his wife Akshata Murthy - currently worth nearly £600 million - quickly followed by education minister Gillian Keegan.
Mr Sunak is greeted like a rockstar by his front bench, throwing high fives and smiles. He stops to laugh at Johnny Mercer’s hiking boots and then he vanishes.
Cue chaos in the corridors as people aren’t allowed to use the stairs and have to wait for two slow-moving lifts - leaving ministers crammed next to Conservative voters.
Outside a solitary Sky producer, sans cameraman and presenter, is waiting patiently as everyone files out of the Excel Centre and onto the DLR.
Admitting he got the moment he wanted, he explains: “We told them we were going on live and they were like ‘we don’t care’.
“We weren’t going to stop filming. It was absolutely ridiculous, absolute nonsense. If they don’t want us here then why did they invite us?
“Now they’ve locked all our stuff away and I have to wait for everyone to clear out before I can pick up my cameraman’s bag.”
Conservative activist Sayeed Zaman, 43, speaking outside the Excel Centre tells me standing in the rain to announce the election is “what a true leader does”.
“I thought it was fantastic. He is the leader of the country - all the journalists had umbrellas but he didn’t need one,” he says.
“He has to accept the momentum of the campaign. He couldn’t predict it was going to rain. It would look bad if there was someone holding a brolly for him. It was brave and what a prime minister does.”
