UK markets fall on Christmas eve, no Santa rally in sight

British shares dipped on Monday as world stocks fell on reports that U.S. President Donald Trump privately discussed firing the head of the Federal Reserve and a partial U.S. government shutdown.

The FTSE 100 was down 0.5 percent and the mid-cap index was 0.8 percent lower, setting a bleak tone for a holiday-shortened week.

Weakness in the dollar weighed on companies with a greater international presence, making them the biggest drags on Britain's main index. HSBC slipped 1.1 percent, while GlaxoSmithKline was 1 percent lower.

Diageo, the world's biggest drinks marker, and consumer goods giant Unilever were down by around 1 percent, while tobacco firms Imperial Brands and British American Tobacco fell 2 percent and 0.6 percent, respectively.

Investors came back to oil stocks following sessions of steep losses in crude prices that hit oil companies. Shell  and BP managed slight gains as oil prices rose on signs the price fall may start crimping supply from the United States.

Most global markets were hit following reports that Trump discussed firing Fed chair Jerome Powell. However, U.S. Treasury Secretary Steven Mnuchin said in a tweet on Saturday that Trump had told him he had "never suggested firing" Powell.

That added to nerves over a partial federal government shutdown as Democrats rejected Trump's demand for more funds for a wall on the border with Mexico.

British indexes are on track for their worst yearly performance since the 2008 financial crisis, as jittery investors dumped shares amid concerns over Brexit, a slowdown in global economy, plunging oil prices and a trade spat between Washington and Beijing.

Britain's mid-cap index, which is more exposed to the outcomes of Brexit, has lost more than 16 percent in the year-to-date and is a little over 1 percent away from confirming a bear market with a 20 percent drop since its peak close in June.

"If 2018 was the beginning of the end of the 10 year bull market, 2019 could well give stocks an additional shove to the downside," CMC Markets analyst Michael Hewson said.

Among the few news-driven moves, mid-cap gambling software company Playtech gave up 7 percent, after earlier hitting its lowest in over six years, as it flagged that a change in Italian gambling tax law would hit its 2019 core earnings.

Gambling companies GVC, Paddy Power Betfair and William Hill also fell between 0.6 percent and 2.1 percent.

Shares in London Stock Exchange were among the top losers on the main index with a 3.9 percent dip after exchanges group Euronext announced plans to buy the owner of the Oslo stock exchange for 625 million euros.

Martin Sorrell's S4 Capital slipped nearly 3 percent on its first trading day on the London Stock Exchange's main market.

Swimming against the tide, Whitbread added 1.3 percent after it said the European Union approved its sale of Costa coffee chain to Coca-Cola Co and announced a 500-million-pound share buyback.