You know you may be right, Jayne. I shall reconsider.

Those last three stanzas only use 3/8ths of your line limit, John, so you could lose the biblical bit and continue with the funny 'now' stuff. There's tons more scope yet - crappy presents, crackers with plastic rubbish in, overcooked sprouts... and lots more - only at Christmastime.

OK. How about this then?


Bah Humbug

At Christmas time we peddle junk
Wrapped up in old religious bunk
And everyone gets very drunk.

At Christmas time my children write
To some old bearded blatherskite
And stay up half the bloody night.

At Christmas time the in-laws come
To drink my whisky, gin and rum
And quarrel with my dad and mum.

At Christmas time my joints are stiff.
They crack and creak. I cough and sniff
And spit into my handkerchief.

At Christmas time my belly vastly
Swells, my temper frays and, lastly,
The weather’s uniformly ghastly.

It's much funnier than the original, John, though I don't care for S4. It's not 'Christmas specific' enough IMO.
And I don't think 'peddle' is quite right either. And... OK, while I'm being so critical (sorry) I wonder whether S3 could be:

At Christmas time the in-laws come;
They quarrel with my dad and mum
And drink my whisky, gin and rum.

From someone who hasn't even got off the starting grid with this one yet... feel free to completely ignore all of the above.

Noted and acted upon. I think I'll stick with the original order for the in-laws though. They drink the booze and THEN they quarrel.


Bah Humbug

At Christmas time I give out junk
Wrapped up in old religious bunk
Before becoming very drunk.

At Christmas time I wonder if
I want to singalong with Cliff.
I think I’d rather be a stiff.

At Christmas time my children write
To some old bearded blatherskite
And stay up half the bloody night.

At Christmas time the in-laws come.
They drink my whisky, gin and rum,
Then quarrel with my dad and mum.

At Christmas time my belly vastly
Swells, my temper frays and, lastly,
The weather’s uniformly ghastly.

Yep, much better without the stiff joints and the 'hanker-chiff', John.

One further suggestion about the in-laws:

How about:

At Christmas time the in-laws come.
They drink me out of gin and rum,
Then quarrel with my dad and mum.

It doesn't matter greatly that there's a 'To' in the same place in S3, but I think the repetition in the first line is sufficient and the other lines need to be a little different from one another.

Scrooged
 

Bah humbug! To Christmas
I'll drink no toast,
though I'm plagued by three spirits
and old Marley's ghost.

Bah humbug! Let Christmas
come on at full throttle.
All the spirits I need
come out of a bottle.

Christmas Down-Under
 

We don't have humbug like you do,
just bug meat on the barbecue.

Christmas is coming,
Politicians getting fat,
Bankers full of Bolly
And the shops are full of tat.

The Nursery School’s Nativity
Is fawningly P C,
Mary’s in a burka
And Joseph is a she.

The Church is full of carollers
In different keys -- and flat,
While muggers steal the pennies
From the old man’s hat.

And underneath the feeble glow
Of eco-Christmas-lights
Some plan its abolition
In the name of Human Rights.

Call it Christmas, call it Yule.
In picking the perfect moniker,
there's just a single, simple rule:
Please don't call it Hannukah.