IN a pitch perfect Disney sequel that will go down as an instant classic, there is one glaring omission in Mary Poppins Returns.

At 93, the original Bert, Dick Van Dyke, returns 54 years on, tap dancing on tables and proving that great entertainers never lose the ability to steal a scene.

But, despite years of begging, pleading, general flattery and even a million dollar offer from movie chiefs, there is no Julie Andrews.

Alas, the woman who to so many quite simply is Mary Poppins was not prepared to give her tacit endorsement to the £150million re-make or her replacement Emily Blunt (even though she has been very publicly polite about her successor).

I have a well-informed theory about the role that had been earmarked for the great actress and singer.

Without giving anything away, one of the heart-expanding, soon-to-be iconic scenes in the new film is when an old woman simply called the Balloon Lady, who features in the Poppins children’s books but not the original movie, sings the soaring second-to-last number Nowhere To Go But Up.

The character, who has a touching exchange with Mary Poppins, is played by Dame Angela Lansbury, now 93 herself.

While she is, without doubt, one of our all-time acting greats, she has had no connection with Mary Poppins in her long career.

The moment is touching enough and I’ll admit my eyes welled up – but just imagine if the scene had featured Andrews, who is 83, effectively passing the baton of playing such a special character to Blunt.

While fans would have loved it, those close to Andrews insist it was simply never going to happen.

Devastatingly, she all but lost her singing voice after botched throat surgery in 1997 – and there was no way she would ever consider miming along to someone else’s voice.

And despite roles in films like Shrek, The Princess Diaries and even this year’s Aquaman, she didn’t want to intrude on what she describes as “Emily’s show”.

As she told director Rob Marshall: “I don’t want it to be, ‘Oh, here comes that Mary Poppins.’”

It might be a painful loss of nostalgia and a bit of a blow to Disney bosses today, but it’s the right decision.