Then "Go" is put with "satellite box for landing", the satellite concerned being the moon, and a box that NASA built for landing on the moon was a Lunar Excursion Module, or L.E.M

So finally you get GO + L.E.M

Groundsman has success with satellite box for landing (5)

G O L E M

"Groundsman" refers to what a golem is - a mythical human-like figure made of earth, mud, clay, the stuff you get from the ground. Thus "groundsman"

"Has success" means GO, in the sense "make a go of it", make a success of it

And . . .

And in those words, Brexit will be over

The only reason Brexit is still being persisted with is vanity. Starmer is the latest, and my guess is the last. Eventually we will get a prime minister free of the entanglements of pride, who looks at the whole mess and says, no more.

Thus:

Overtaken in poll I'd accept with some small error (10)

PECCADILLO

The answer is written out in the clue. If you pick out the words

"P /OLL I'D ACCEP /T

You'll see it written backwards, as indicated in the clue where "Overtaken in . . ." tells you that the answer is found in the phrase or error "poll I'd accept"

And a peccadillo is a small fault, or "error"

The answer to today's clue was, of course, PECCADILLO

"Overtaken in poll I'd accept with some small error"

(explanation follows . . .)

Thus:

8 Across: Workman turning one out of last chance saloon given pat on the back (5,5)

EDWIN DROOD

And finally "given pat on the back" means WIND, as with a baby, pat it on the back to WIND it.

So: ED-RO-OD becomes ED-WIND-RO-OD

EDWIN DROOD

"Workman" means the title character of a work of fiction. So, Edwin Drood in this case.

"Turning one out of last chance saloon" means "turning one out" - removing the letter "I" - from another expression meaning "last chance saloon", which is DO OR DIE

Leaving "DO OR DE"

And "turning" ED-RO-OD

Bat = x, ball = y

x + y = 110

2y + 100 = 110

2y = 10

y = 5, x = 105