The impending birth of Prince William and Kate Middleton's second child is predicted to spark a significant tourism influx to London, as visitors flock to experience all things royal.

The new Prince or Princess will be born at St Mary’s Hospital in Paddington, where well-wishers have already started to gather. Meanwhile, leisure businesses across the capital are beginning to offer monarchy-themed promotions as they bid to capitalise on the feel-good factor.

The Park Lane Hotel is now hosting a Royal Baby Shower Afternoon Tea, where guests can indulge in tasty treats such as a hazelnut and polenta pram cake or a milk bottle panna cotta. London Hilton on Park Lane is providing a similar service, while royal-themed river cruises and experiences are beginning to be offered on the Thames.

Gordon Innes chief executive of London & Partners – the mayor’s official promotional company for London – believes baby fever will help the UK register yet another record year for inbound tourism, as it did when Prince George was born in 2013.

“The year of HRH Prince George’s birth was a record-breaking year for tourism, with London welcoming almost 17 million international visits in 2013,” said Innes.

“Royal occasions such as this, combined with a continually spectacular and diverse tourism offering in London, help boost visitor numbers to the city and maintain London’s position on the world stage – and we are anticipating that the capital will welcome 2.7 million more international and domestic visits in 2015 compared to 2013.”

The last three years have brought a raft of major royal events that have increased interest in Britain’s royal family. These have included the wedding of Prince William and Kate Middleton, the birth of Prince George and the Queen’s Diamond Jubilee celebrations. Previous estimates have placed the impact of royal tourism to be worth more than £500m a year, although that figure is expected to now be significantly higher.