He’s been there long enough for the batches of mail from all over the world to come addressed to him at “the tent outside the Islamic Republic of Iran embassy”.

As the hunger strike undertaken by Richard Ratcliffe in support of his wife approached the two-week point, however, he was candid about its physical impact.

“I’m OK but I feel the cold more, have less energy and get tired in the afternoons,” said Ratcliffe, whose spouse, the Iranian-British dual national Nazanin Zaghari-Ratcliffe, is serving a five-year prison sentence in Iran for espionage and is herself on hunger strike in protest at her conditions.

“I can also be quite slow-witted. You notice it not so much in newspaper interviews, but on television sometimes there will be a proper pause if I get a tricky question. There is a point at which you get a strange taste in your tongue but I haven’t got that yet.”

By now, the pavement outside the embassy across the road from Hyde Park in London has been turned into a small hub of colourful protest with its own rhythms and routines. The mid-morning arrival of a postal worker wheeling a trolley with post for the embassy and Ratcliffe is one, shortly before the switchover by armed diplomatic protection police.

The backdrop is a large corrugated iron barrier erected by the embassy in an attempt to block off Ratcliffe, which has become a useful board on which to place the hundreds of cards and messages sent to him.

There are bouquets of flowers, mainly from British-Iranians, a garden gnome bearing the slogan “Free Nazanin” and three tents in which he, friends and members of his family spend the nights. At the beginning, the embassy appeared to have tried to wrongfoot the protest – power tools were turned on as interviews started and railings suddenly needed to be painted – but now figures emerge and swiftly walk on down the pavement without a glance.

Facebook Twitter Pinterest Richard Ratcliffe in front of the barrier erected by the Iranian embassy in an attempt to block him. Photograph: Martin Godwin/The Guardian

In a stream of people which steps up a gear from late morning, comes the periodic arrival of politicians, faith leaders, old school friends and compete strangers.

By noon on Friday the visitors ranged in age from 85 – Beryl Hunter, who had taken the train from Aylesbury with letters from other residents of the care home in which she lives – to the two teenage boys doing work experience at the Thomson Reuters Foundation, which employs Zaghari-Ratcliffe as a project manager.

Others included friends Daniella Selig and Katherine Bellau, who said: “We’re around the same age as Nazanin and have children as well, so while we can only begin to imagine what she’s going through, there’s a sense of empathy.”

“We just wanted to come along to show our support in any way. We both have 12-year-olds and even they are aware of this,” added Selig.

Among those greeting the visitors and keeping an eye on Ratcliffe as he divided his time between media interviews and standing or sitting for photographs was one of his brothers, Chris, and their mother, Barbara, 68. Ratcliffe’s sister, a GP, has also been on hand to monitor his health, while a number of eminent medical professionals with expertise in the effects that going without food have on the body and how to recover from it have also dropped by to offer advice.

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“When it comes to an end I’ve been told that I just have to get him into a taxi and go straight to A&E,” said Ratcliffe’s mother.

“Of course, he knows that we are all absolutely terrified for him, but in other ways this has been different from what I had expected. The sheer amount of support and goodwill, particularly from Iranians, has been overwhelming.”

Facebook Twitter Pinterest Notes of support outside the Iranian embassy. Photograph: Dan Kitwood/Getty Images

Ratcliffe talks about how the experience has been “emotionally uplifting” but was looking forward to the phone call he was due to have with his wife on Friday or Saturday after last speaking to her on Monday.

“If she tells me that she’s ending it then I will, but if she’s not then I’m not. It’s completely in her hands,” he added.

“The longer she goes on the more worried I’ll get. Whilst I had a bit of middle-aged spread she doesn’t and actually that’s quite important. It’s what you’re living off.”

Foremost in both of their minds, meanwhile, is their daughter, Gabriella, who is with Zaghari-Ratcliffe’s mother in Tehran.

“She needs two parents. Part of the reason why I did this as a joint hunger strike was to slow Nazanin down. If she got really angry I didn’t want her suddenly doing it alone. She wanted to make a point and I think she has done that.”