Anyone help me find a horsey poem - driving me mad

[Pinkwellies2]

I vaguely remember there being a horsey poem, bit of a mickey take of pony club, which started something like
"Its awfully bad luck on Diana" and think ended with the speaker having a broken collarbone.
I cant remember what it is called and my internet search has been fruitless - please can anyone help

 

[philamena]

It was John Betjeman, great poem.

It’s awf’lly bad luck on Diana,
Her ponies have swallowed their bits;
She fished down their throats with a spanner
And frightened them all into fits.

So now she’s attempting to borrow.
Do lend her some bits, Mummy, do;
I’ll lend her my own for to-morrow,
But to-day I’ll be wanting them too.

Just look at Prunella on Guzzle,
The wizardest pony on earth;
Why doesn’t she slacken his muzzle
And tighten the breech in his girth?

I say, Mummy, there’s Mrs. Geyser
And doesn’t she look pretty sick?
I bet it’s because Mona Lisa
Was hit on the hock with a brick.

Miss Blewitt says Monica threw it,
But Monica says it was Joan,
And Joan’s very thick with Miss Blewitt,
So Monica’s sulking alone.

And Margaret failed in her paces,
Her withers got tied in a noose,
So her coronets caught in the traces
And now all her fetlocks are loose.

Oh, it’s me now. I’m terribly nervous.
I wonder if Smudges will shy.
She’s practically certain to swerve as
Her Pelham is over one eye.

* * *

Oh, wasn’t it naughty of Smudges?
Oh, Mummy, I’m sick with disgust.
She threw me in front of the Judges,
And my silly old collarbone’s bust.

 

[philamena]

Should have said, it's called Hunter Trials.

 

[Pinkwellies2]

Thats the one, brilliant thank you ever so much.