Nic Jones got this song from the Journal of the Folk Song Society (No. 8, 1906).  It was noted in Essex.  The song is more usually known as Oxford City or Poison in a Glass of Wine.

NEWPORT STREET

In Newport Street it was reported,
A comely woman there did dwell;
And by a serving man was courted,
Who loved this lady exceeding well.

He says, "My dear, let us get married!
Oh dearest love, don't you dislike me;
I'll work for you both late and early,
If you my wedded wife will be."

She says "Kind Sir, let us consider;
We are both yet too young to wed.
When we are married we're bound together;
Let us live single for another year."

But then he saw her dancing with some other;
A jealous thought ran into his mind.
For to destroy his own true lover,
He gave her poison in a glass of wine.

She drank the wine and then she halted;
"Oh dearest love, oh and pray take me.
That glass of wine you just now gave me,
Makes me as sick as I can be."

As they were walking home together,
These very words he told to her:
"That glass of wine I just now gave you,
It will soon take your sweet life away."

Other references.  In the DT:

Oxford City  From the Penguin Book of English Folk Songs, with tune.

Jealousy  From The Constant Lovers, ed. Frank Purslow (EFDS, 1972).  Tune and last 4 verses from George Blake of Southampton, 1907; remaining verses from Henry Lee of Whitchurch, Hampshire.

At  The Traditional Ballad Index:

Oxford City [Laws P30]

At  Bodleian Library Broadside Ballads:

The Newport street damsel  Printed between 1817 and 1828 by T. Batchelar, Long Alley, Moorfields, London.  This is substantially the same as the traditional set that Jones used, though it has a concluding verse:

And I myself will take another;
O, what a silly man was he,
So in each other's arms they died!
Young men beware of jealousy.

There are 19 examples of Oxford City, a little longer but all substantially the same.  Here is one:

Oxford city  Printed between 1813 and 1838 by J. Catnach, 2, Monmouth-Court, 7 Dials, London.

Final verse:

And I have drunk the same my jewel,
I soon shall die as well as thee,
Then in each other's arms they died,
Young men beware of jealousy.

Malcolm