Just days before firefighters go on strike tomorrow West Hampstead’ intrepid heroes have lived up to their reputation for being ready for anything in the line of duty.

Three-year-old Eli Klive found this out on Saturday when, after letting go of his precious birthday balloon, nearby officers stepped in to help.

The birthday boy was inconsolable as he watched the red balloon become trapped in a vaulted ceiling 30ft above his head in Pizza Express, West End Lane.

As Eli stared forlornly up at his lost present, his party stalled as his dad Alx tried in vain to find a solution. It was time to bring in the big boys.

Bribed with pizza and the knowledge they’d be saving a little boy’s birthday, West Hampstead fire station’s Blue Watch popped a few doors down to save the day.

Within minutes their specialist equipment – a long stick with a hook on the end – had the balloon down from the ceiling and delighted smiles were back on every face.

Richard Magnus, crew manager at the watch, said: “We will do anything for anyone in our community who needs our help. In this case, it was a lovely little boy who had lost his balloon.

“Luckily we have great relationship with Pizza Express and they were happy to have us come in and retrieve the balloon – and we had the perfect equipment to save the little boy’s birthday.”

The hero who reached the runaway balloon was firefighter Rob Masters. And although Mr Magnus said they were proud of helping the party, at no point did the balloon come before their ability to respond to emergencies.

He said: “They made a hysterical little boy jubilant and, all the time the guys were just next door to the station, so still available for any emergency that might occur.”

Mr Klive said the birthday party was made by the “Fireman Sam”- style rescue.

He said: “I think it was a mixture of excitement from the firemen and happiness at getting his big balloon back – as Eli was suddenly very, very happy again.

“There must have been three different kids’ parties there on Saturday – so the excitement spread through the whole restaurant.

“It was really great of the firemen to come and save the day.”

The West Hampstead firefighters helped out despite currently working-to-rule – an industrial action in which employees do no more than the minimum required by the rules of workplace.

They are protesting over shift changes which they say pave the way for sackings. The Fire Brigade denies this is the case.

The Fire Brigades Union (FBU) said 79% of its members who voted had supported strike action.

Firefighters across London are due to go on full strike on Tomorrow, Saturday and Monday November 1. A private company is due to be put in charge of services to cope with the walk-out.