Gloucestershire will need a miraculous backs-to-the-wall batting performance on the final day at Lord's to prevent Middlesex securing their second win of the LV County Championship Division Two campaign.

The West Country county go into Sunday's fourth day teetering on 55 for three and still requiring a further 351 for victory having already lost Robert Woodman, New Zealand all-rounder Hamish Marshall and Alex Gidman cheaply in the 16 overs through to Saturday's close.

Facing a victory target of 406 after Shaun Udal's declaration, Gloucestershire saw opener Woodman go leg before to Tim Murtagh's fourth ball of the second innings then, two deliveries later, Murtagh had Marshall caught at the wicket for a duck to leave the visitors in trouble on four for two.

Alex Gidman survived two scares before he fell leg before wicket to Steve Finn when pushing at a delivery which appeared to keep a little low to make it 21 for three.

Kadeer Ali (20) and Chris Taylor (16) limped through to stumps but Middlesex will go into the final day firm favourites to win this their 13th game of the season.

Batting again by 11.25am having already secured a first innings lead of 132, Middlesex - without Eoin Morgan, Andrew Strauss and Owais Shah on England duty - were hampered further by the absence of Australia-born opener Sam Robson.

The 20-year-old from New South Wales was unable to bat after chipping a bone in his elbow when taking a slip catch to remove Stephen Adshead yesterday afternoon.

Surprisingly Murali Kartik, with only one 50 to his name this summer and who batted at nine in the first innings, was promoted to open alongside Nick Compton.

Udal's ploy worked, however, as the makeshift openers added 128 in 35 overs either side of lunch to effectively bat Gloucestershire out of the game.

Kartik had his feathers ruffled after being struck on the left shoulder by a Steve Kirby bouncer, but the Indian left-hander bravely fronted up thereafter to score an excellent 57 from 105 balls.

The opening partnership ended when Kartik, in trying to boss the off-spin of Richard Dawson, advanced and missed to gift Adshead a stumping.

Debutant Adam London was run out for 11 when wanting a second run to midwicket then, seven balls later, Compton went for 83 for the second time in the match when miscuing an attempted pull to Ian Saxelby at midwicket.

Winter signing Neil Dexter and left-hander Dawid Malan took the home lead beyond 300 in adding a further 29 before Malan, in trying to force the pace against off-spinner Chris Taylor, dragged the ball onto his stumps via an inside edge making it 191 for four at tea.

After the break Scott's attempted run down against Saxelby was edged to Dawson in the cordon then, 11 runs later, Gareth Berg edged an attempted drive against Kirby into the gloves of Adshead and was on his way for seven.

Dexter chipped in with an unbeaten 39 and Udal with a quickfire 26, including a huge six off Taylor into the top tier of the Grandstand which necessitated a ball change and took the home lead beyond 400.

But Udal holed out to spark his declaration at 5pm on 373 for seven, leaving Gloucestershire to survive an hour and Sunday's three sessions or score an unlikely 407 for victory.

Middlesex had needed the first 17 minutes of the day to break Gloucestershire's dogged 10th wicket stand between Jonathan Lewis and Kirby, which added 32 runs and helped them avoid the follow-on.

Kirby (18) was the last man out, edging to Dexter at slip to give Murtagh first innings figures of four for 61.

Taylor easily top-scored for the visitors with 65, ahead of the 30 extras conceded by the hosts.