At 0830 GMT, the FTSE 100 was down 0.6% at 7,258.79.
Susannah Streeter, senior investment and markets analyst at Hargreaves Lansdown (LON:HRGV), said: "The control of US Congress hangs in the balance today as the mid-term elections are set to take place, but already the markets appear to be pricing in a Republican victory.
"Although the final polls pointed to an increasingly competitive political landscape, worries about the economy are looming large in this campaign, hinting that there could be trouble for Democrats in the Congressional race and in the fight for seats up for grabs in the Senate, especially with Joe Biden remaining unpopular."
On home shores, industry research showed that retail sales growth slowed in October as the mounting cost-of-living crisis curbed spending.
According to the latest BRC-KPMG Retail Sales Monitor, total sales rose by 1.6% in October, compared to a rise of 2.2% in September. The figure was below both the three-month average of 1.7% and 12-month average of 2.7%.
On a like-for-like basis, sales rose 1.2% year-on-year, compared to a 1.8% rise in September. That was largely in line with the three-month average of growth of 1.2%, and ahead of the 12-month average of 1.0%.
Helen Dickinson, chief executive of the British Retail Consortium, said: "As the cost of living for consumers continued to rise, retail sales slowed in October. With November’s Black Friday sales just around the corner, people look to be delaying spending, particularly on bigger purchases.
"Clothing and footwear, which saw stronger sales this year, declined as the mild weather meant customers held back on buying winter outfits."
The last three months of the year is crucial for many retailers, as shoppers splash out on festive treats.
But Dickinson warned: "Christmas will come later than last year for many, and may be more gloom than glitter as families focus on making ends meet, particularly as mortgage payments rise."
In equity markets, housebuilders were the standout losers as Persimmon (LON:PSN) warned of fewer completions and a hit to margins from falling house prices amid the cost-of-living crisis. The company said cancellation rates had risen to 28% from 21% in the last six weeks after the government’s disastrous mini budget - which saw thousands of mortgage offers pulled from the market - and rising interest rates.
Persimmon slumped more than 8%, while Taylor Wimpey (LON:TW), Berkeley, Barratt Developments (LON:BDEV), Vistry, Redrow (LON:RDW) and Bellway (LON:BWY) also lost ground.
Hilton Foods slid as it warned that full-year profits would be below its expectations due to challenges in the UK seafood business and the wider macroeconomic environment.
Insurer Direct Line was also in the red as it posted a decline in gross written premiums, pointing to a challenging market backdrop for the motor and home segments. Admiral also fell.
On the upside, soft drinks bottler Coca-Cola (NYSE:KO) HBC rallied after it raised full-year earnings guidance as it reported a boost to revenue from rising prices in the third quarter.
Associated British Foods (LON:ABF) also gained after it reported a jump in full-year sales and profits despite surging input cost inflation, following a bumper performance at its budget fashion brand Primark.
Elsewhere, Hammerson pushed higher after a well-received third-quarter trading update, while Babcock was boosted by an initiation at ‘buy’ by Berenberg.
Market Movers
FTSE 100 (UKX) 7,258.79 -0.56%
FTSE 250 (MCX) 18,504.87 -0.29%
techMARK (TASX) 4,283.80 -0.05%
FTSE 100 - Risers
Coca-Cola HBC AG (CDI) (CCH) 1,982.00p 2.93%
Associated British Foods (ABF) 1,470.00p 2.91%
Lloyds Banking Group (LON:LLOY) 42.32p 0.74%
National Grid (LON:NG.) 962.40p 0.69%
Barclays (LON:BARC) 153.62p 0.67%
BT Group (LON:BT.A) 115.85p 0.56%
Pearson (LON:PSON) 950.40p 0.27%
Airtel Africa (AAF) 121.00p 0.25%
Haleon (HLN) 279.25p 0.23%
Pershing Square (NYSE:SQ) Holdings Ltd NPV (PSH) 2,910.00p 0.17%
FTSE 100 - Fallers
Persimmon (PSN) 1,206.00p -8.84%
DCC (CDI) (LON:DCC) 4,638.00p -6.19%
Admiral Group (LON:ADML) (ADM) 1,908.00p -3.85%
Taylor Wimpey (TW.) 93.00p -3.61%
Berkeley Group Holdings (The) (BKG) 3,474.00p -2.96%
Barratt Developments (BDEV) 374.40p -2.93%
Kingfisher (LON:KGF) 219.80p -2.48%
JD Sports Fashion (JD.) 102.35p -1.96%
Ocado Group (LON:OCDO) 661.00p -1.96%
Glencore (LON:GLEN) 523.20p -1.65%
FTSE 250 - Risers
Hammerson (HMSO) 23.61p 9.92%
Babcock International Group (LON:BAB) 288.20p 5.18%
3i (LON:III) Infrastructure (3IN) 333.50p 4.38%
Rotork (LON:ROR) 285.40p 2.59%
888 Holdings (DI) (LON:888) 103.60p 2.07%
BlackRock (NYSE:BLK) Smaller Companies Trust (BRSC) 1,326.00p 2.00%
C&C Group (CDI) (CCR) 168.30p 1.88%
Vietnam Enterprise Investments (DI) (VEIL) 544.00p 1.68%
IMI (LON:IMI) 1,341.00p 1.59%
Network International Holdings (NETW) 341.00p 1.43%
FTSE 250 - Fallers
Hilton Food Group (HFG) 588.00p -7.26%
Direct Line Insurance Group (DLG) 188.50p -5.47%
Vistry Group (LON:VTYV) (VTY) 599.50p -3.46%
Synthomer (LON:SYNTS) (SYNT) 124.40p -3.12%
Domino's Pizza Group (DOM) 233.80p -2.83%
ASOS (LON:ASOS) (ASC) 630.00p -2.63%
Redrow (RDW) 430.00p -2.58%
Future (FUTR) 1,323.00p -2.43%
Ibstock (IBST) 153.00p -2.42%
Bellway (BWY) 1,913.50p -2.42%
