UPDATE 2-FTSE 100 hits one-month high; Brexit tussle bogs down midcaps

* FTSE 100 up 0.7%, FTSE 250 flat

* Oil, miners drive gains on main index

* BAT benefits from FDA ruling on Swedish Match

* Fresnillo slips after weak outlook
(Adds news item, updates to closing prices)

By Muvija M and Shashwat Awasthi

Oct 23 (Reuters) - Shares in domestically-focused UK firms
eased on Wednesday as votes in parliament kept investors
guessing on the final timing and shape of Britain's withdrawal
from the European Union, while the blue-chip FTSE 100 touched a
near one-month high.

The FTSE 100 climbed 0.7%, hitting its highest since
Sept. 25, as oil majors tracked gains in crude prices and miners
benefited from a rise in nickel and copper prices.

The blue-chip bourse outperformed its European peers, aided
by a rise in shares of BAT after the U.S. FDA
authorized Swedish Match to market its snus product as
less harmful compared with cigarettes.

The mid-cap index ended flat after spending most of
the session in the red as uncertainty around Brexit and its
consequences continues to show up in the performance of domestic
companies.

Housebuilders, considered among the most vulnerable, were
hit as Barratt, Persimmon and Berkeley
shed around 2% each while UK-focussed RBS tumbled nearly
3%.

Britain's parliament accepted a Brexit withdrawal deal in
principle on Tuesday but scuttled Prime Minister Boris Johnson's
timetable to legislate on the agreement before a Oct. 31
deadline.

While lawmakers voted for a second hearing on the departure
agreement, rejection of Johnson's timetable raises the
likelihood of another delay in Britain's withdrawal as well as
the prospect of a snap election before Christmas.

"The latest twist in the Brexit saga also means that
investors may have to contend with more political risk by way of
a UK election," said Han Tan, Market Analyst at FXTM.

Raymond James analyst Chris Bailey called the Brexit
situation "a mess" overall and said the core scenario of an
extension or an election was becoming more likely.

Precious metals miner Fresnillo gave up 1.7% after
it forecast annual silver and gold production at the lower end
of an already reduced target range, and reported a fall in
quarterly output.

Centamin shone on the FTSE 250 with a 4.2% gain
after its third-quarter production fell less than feared.
(Reporting by Muvija M and Shashwat Awasthi in Bengaluru;
Editing by Shounak Dasgupta, Patrick Graham and Alexandra
Hudson)