Fears that Ladbrokes could be forced to shutter loss-making bookies sent the betting group tumbling nearly 5 per cent.
JPMorgan Cazenove's analysts gave their take on the Government's comments on the restricting of gaming machines. JP's experts warned Ladbrokes is at "significant risk" and cautioned if "even modest restrictions were imposed on the machines" Ladbrokes' "bottom 20 per cent of shops could become made loss-making". Investors took their bets off the table and Ladbrokes lost 8.1p to 158.6p.
The benchmark index edged closer to an eight-month high during the day but dipped back into the red before the close.
David Madden, a market analyst at spreadbetter IG, said: "Minerals extractors tried their best to pull the market down as metal prices took a dive."
The FTSE 100 slipped 2.47 points to 6,834.26.
One of the top risers was quality checker Intertek after Swiss testing and inspection firm SGS raised its dividend and growth forecast. Intertek collected 92p to 3,000p.
Analysts at HSBC issued a report on the commercial property sector and said the "resurgent UK economy is on the cusp of spurring rental growth and leading UK commercial real estate into phase three of its recovery – a phase of prolonged and sustainable capital value growth".
Blue-chip property group British Land picked up 11p to 672.5p, Land Securities advanced 11p to 1,045p and Hammerson was 5.5p higher at 525p.
Confirmation that engineers Melrose Industries and IMI are returning around £1.2bn to shareholders helped Melrose ahead 2p to 313.7p but IMI fell 13p to 1,538p.
On the mid-tier table miner African Barrick Gold said it had exceeded 2013 gold production guidance and was 5.9p brighter at 206.5p.
Petra Diamonds said it had dug up a 29.6-carat blue diamond from South Africa's Cullinan mine and it sparkled 2.5p better at 125p.
Interactive whiteboard maker Promethean said it expects its 2013 results to be ahead of expectations. The shares jumped 4.125p to 29p, still way below its 200p 2010 float price.