A national icon, playing a national icon, about a national icon can make for some heavy adulation.

I suspect some members of the audience for this National Theatre and Wales Millennium Centre co-production starring Michael Sheen as Nye Bevan, founder of the NHS, were there for those three reasons, or at least one or two if not all three.

This did give the performance and the audience reaction something of a revivalist meeting feel, particularly as playing the titular character there was much of Sheen’s characteristic near Messianic personality shining through.

Unfortunately, these elements also were a weakness of Tim Price’s new play; reducing historic events, debates, major failures that accompanied the successes (such as surrendering to the BMA with the resultant and contemporary inability for the NHS to properly function) to a mixture of pantomime scenes, lampoons, or rapidly past over anecdotes.

This is also partly due to Rufus Norris staging and Vicki Mortimer’s set designs.

Using the dramatic conceit of the play being a morphine-induced flashback as Bevan lay dying in a hospital bed, the above criticisms can be explained by the man’s life being seen through this drug haze.

However, the play also has dialogue involving Nye and other people around his hospital bed, his wife Jenny Lee, played warts and all by Sharon Small, long-time stalwart Archie Lush, played by Roger Evans, and the hospital medical staff in the “non dream world”.

In some ways these are the most effective as some dreadful truths, confessions, soul searching, resentments, disappointments, are all exposed, while Bevan slowly slips into death.

Another concern is how much you need to know about the historical context of the Welsh politician’s long political life, including the ugly latter periods when party political reality exposed the contradictions between idealism and the horrible real world.

These were touched upon very effectively in the scenes where Bevan is played by members of his own party and how to get his dream of an NHS into reality, he accepts those shackles that still drag the system down, the demands of the BMA and protectionism of its members.

Oddly it is at this point the audience burst into applause. Inside some of us felt our hearts sink at the problems that lay ahead and still lie ahead.

However, this is a piece of theatre and could have been even more evangelical.

Instead, it focussed, rightly, on the man, his huge strengths and did not shy away from his significant weaknesses (and those of his wife). How the stuttering child became the orator, the strike leader became a government minister, the man whose horror at his father’s grim illness and early death drove his mission.

Splendid acting from those others in his life, frequently playing at least two roles, added an extra dimension, the long-suffering sister Arianwen played by Kezrena James becoming the caring nurse, Tony Jayawardena’s Winston Churchill becoming the consultant surgeon Dain, and the gender twisting Clement Attlee from Stephanie Jacob becoming the ward matron.

Rhodri Meilir was knuckle-clenching strong as Nye’s dying father and rather mystical figure when the father and son were at the coalface as miners.

Nye, from National Theatre and Wales Millennium Centre is at the Wales Millennium Centre until June 1