Kate Middleton Catherine Duchess of Cambridge
Kate Middleton's is due to give birth in late April Getty

Parking restrictions near the hospital where the Duchess of Cambridge is due to give birth to her second child have prompted further speculation that the royal baby is due by the end of April.

The parking restrictions, posted on yellow signs outside the private Lindo wing of St Mary's Hospital in Paddington, will run until 30 April.

While the birth of the new arrival might well coincide with the Queen's birthday on 21 April, or William and Kate's fourth wedding anniversary on 29 April, going by the parking restrictions set in place, the Duchess will have given birth by 30 April.

Her due date has not been confirmed, but in March, Middleton told a volunteer at a south London charity that the baby was due "mid-April, to the end of April".

Prince George was also born at the Lindo Wing two years ago, the same hospital where Princess Diana gave birth to both her sons William and Harry.

As a returning mother-to-be, the Duchess will be given 10% off the Lindo Wing's £6,570 a one-night fee as part of a loyalty discount to mothers who go back to have a second child.

Her care at St Mary's will be led by surgeon-gynaecologist Guy Thorpe-Beeston.

Official confirmation that the Duchess is in labour is expected to come from Kensington Palace once she has been admitted to hospital.

The sex of the fourth in line to the throne has not been revealed, though the Duchesses craving for sweet desserts and the recent delivery of pink paint to Kensington Palace, have fuelled speculation that the Duke and Duchess of Cambridge are set to welcome a baby girl.