Britain's Olympians had to wait four anxious, fingernail-gnawing days to celebrate their first gold medal. Those in charge of Britain's Paralympic team will be getting edgy if the country has not welcomed its first gold within a matter of hours of the Games beginning this morning.

If Britain is to meet its medal target – and failure to do so will have financial consequences just as in the Olympic sports – it will require one to be delivered around every hour of competition over the next 11 days. It appears to be a demanding challenge, but it is accompanied by a widely held expectation that it will be met, and in some quarters met with a degree of comfort. One bookmaker is quoting a price of 1-16 that Britain will win the 103 medals that would satisfy their UK Sport funders.

There is ample reason for optimism, but one that is weighed by the sheer scale of the task and lack of margin for error; a medal drought would be a couple of hours without sight of the Union flag being raised somewhere around the Olympic Park or over the other outlying venues.

"We are quietly confident," said Penny Briscoe, Britain's deputy chef de mission. "That pressure is there. That expectation is there but we are used to dealing with that pressure."

While comparisons with the Olympics are something those in the Paralympics quickly tire of, it does offer a suggestion as to how the home athletes might fare. "There is no doubt that the passionate support of the home crowd inspired Britain's athletes to achieve our greatest medal haul for over a century," said Andy Hunt, chief executive of the British Olympic Association, yesterday.

Hunt believes, and is far from alone in doing so, that the crowd – which will assemble in similar numbers around the venues (2.4 million of 2.5 million tickets have been sold) – can have a similarly positive affect. It is a view echoed by Paralympic athletes who have waited and waited for their chance. Ellie Simmonds, who begins her campaign to defend her Beijing gold medals on Saturday in the 400m freestyle, grinned and nodded when asked if she was having to stop herself from bouncing off the walls.

Simmonds and the other 43 swimmers have been tasked with delivering the bulk of Britain's medals, between 40 and 50 in all. It was, to return briefly to the Olympics, in the pool that Britain suffered its only major disappointment, with a number of identified medal hopes failing to cope with the expectation and sheer scale of the occasion. Simmonds, for one, is confident of not suffering a similar fate.

The 17-year-old is one of eight Beijing gold medallists swimming again for Britain, while there are another nine who won medals four years ago – including Jonathan Fox, who could claim Britain's first gold in the pool tonight. Their ranks are bolstered by a number of rising talents, Susie Rodgers, who won five golds at last year's European Championships, is particularly highly thought of, as is Daniel Pepper, a double gold winner at the 2010 World Championships.

Swimming will also produce the most personal duel in the pool, beginning tomorrow night when Sam Hynd, the 400m freestyle defending champion, faces strong competition from a familiar figure, his younger brother Oliver, who is making his Paralympic debut.

For the first British medals, though, look as ever to the country's most reliable sport, be it Olympic, Paralympic, home or abroad (having kept half an eye on the veteran Di Coates, in her eighth Games, as the shooting ends around midday). This afternoon in the Velodrome Darren Kenny, Rik Waddon and Mark Colbourne will have the first golden opportunity and should they pass it up Sarah Storey, one of Britain's great Paralympians, is unlikely to.

The worry for the cyclists, and this is one that has echoes across the Paralympic sports, is the Chinese. China's Paralympians rarely compete outside their own country in between Games and so come into the event as something of a mystery.

"They are a very private nation," said Waddon. "They surprised our guys in Los Angeles at the World Championships this year in the team sprint, an event we have dominated for seven years. That was a shock."

China were comfortably the leading nation on home soil four years ago, winning more than twice as many golds and twice as many medals as Britain. They have sent a smaller team to London –Britain's 300-strong contingent is the largest – and seem certain to suffer a decline in their medal tally. It would seem improbable that they would fall far enough for an improving Britain to bridge the gap but the hosts should significantly close it and should certainly maintain a strong grip on second place.

"There are 16 new countries taking part this time but Britain has hung on in there," said Tanni Grey-Thompson, striking a note of caution. "In the early years, when the Paralympics was not a worldwide sporting event, it was easier to be higher up the medal table but second place is still realistic."

For Grey-Thompson there will be one athlete she might be paying particularly close heed to. Lee Pearson has nine Paralympic golds to his name and is chasing three more, which would take him past Grey-Thompson as Britain's most successful Paralympian. "I get embarrassed about how many medals I've won," said Pearson, the 38-year-old dressage rider. "It's about the talent I was born with. I always say I'm one of the most normal abnormal people you'll ever meet."

Top ten Brits who can light up the Games

Jonnie Peacock

The 18-year-old from Cambridge has already made Oscar Pistorius eat his words – that according to Pistorius himself – having made dramatic improvements over the last year to force his way into gold medal contention in the T43/44 class. Another who was first spotted at a talent day, at Mile End Stadium, barely a mile from the Olympic Stadium where he will race against Pistorius and Co in the 100m. In June Peacock set a new T44 world record in a guest appearance at the US trials.

Tom Aggar

A former rugby player, Aggar turned to rowing after breaking his back in an accident seven years ago. Made his Paralympic debut in Beijing and won gold only two years after taking up the sport. He has underlined his dominance of the "arms and shoulders only" single sculls through winning the world title every year since. In all he has now won the world title in 2007, 2009, 2010 and 2011 and is a strong favourite to add a second Paralympic title in London.

Aileen McGlynn

The Glaswegian is based in Manchester alongside the rest of Britain's elite cyclists, be they Olympians or Paralympians. The 39-year-old is riding in her third Paralympics and looking to defend the two titles she won in Beijing, the individual pursuit and the time trial. She is riding with a new pilot in London, with Helen Scott having replaced Ellen Hunter, with whom McGlynn also won gold in Athens in 2004.

Danielle Brown

Since winning gold on her Paralympic debut in Beijing, Brown has assembled a garlanded curriculum vitae. It includes an archery team gold medal which was won at the Commonwealth Games, where she became the first Paralympian to compete for England in a non-disabled event, beating the cyclist Sarah Storey by a matter of days. The 24-year-old, who is based in Shropshire, where she trains at the National Sports Centre in Lilleshall, has won gold at the last two World Championships.

Lee Pearson

The 38-year-old from Stoke has been to three Paralympics, competed in nine events and won nine gold medals. The dressage rider will go in three more events in London – the team, individual and freestyle – and three more gold medals will take him past Tanni Grey-Thompson's total of 11 and make him Britain's most successful Paralympian.

Dave Clarke

He is a golden boot winner at three World Cups and has scored 126 international goals, but Clarke has still to win a major honour. A runners-up medal from the European Championship three years ago represents the 41-year-old's best finish. Britain's five-a-side team came fifth in Beijing and will depend on Clarke's goals to improve on that. He is the man in form – he was top scorer at last year's European Championship.

Ellie Simmonds

The British face of the Games and she is relishing it. Came from nowhere to win two golds in Beijing – she had been selected with a long-term view to London 2012. She goes in four events and, having set the first world record in the Olympic pool earlier this year, appears to be in the form to repeat the successes of her debut. Still only 17 but utterly unfazed by the spotlight cast upon her.

Susie Rodgers

Rodgers will compete in five events in the Aquatics Centre, the same number of golds she won in the European Championships in Berlin last year. That was her first major championships and she proved Britain's surprise success, winning six medals in all and breaking two European and one British record en route. Rodgers came relatively late to elite sport – she is 29 and juggles her swimming career with a job at the British Council.

Jody Cundy

One of British Paralympics' great all-round athletes. London will be Cundy's fifth Games and second as a cyclist. His first three, Atlanta, Sydney and Athens, were as a swimmer – he won three golds and two bronze. Switched to cycling for Beijing and won two golds, the team sprint and the time trial. The 33-year-old will go for another two golds in London, in the pursuit and the time trial.

Hannah Cockroft