London midday: Retail stocks buoy markets led by M&S, but upside limited

London's stocks edged higher on Thursday ahead of the long weekend, helped in no small part by strong gains in the retail sector.However, gains were only modest as developments in Greece and uncertainty ahead of a live political debate in the UK weighed on sentiment. Meanwhile, mining stocks weakened as iron ore prices dropped.The FTSE 100 was trading just 0.1% higher at 6,816.03 by midday.Greece was once again under the spotlight after Athens submitted a new proposal of economic reforms overnight "which is more specific and quantified", according to the Greek finance ministry. The 26-page document suggests that Greece could raise as much as €6bn this year as it looks to unlock €7.2bn in bailout funds before it runs out of money.Nevertheless, EU officials claimed the new list still needs more work and a deal is not expected before the next meeting of Eurozone finance ministers on 24 April.Meanwhile, Thursday night will see the leaders of the seven top political parties in the UK battle it out in a live, televised debate in the run-up to the general election in May.In fact, political uncertainty was cited as one of the reasons why growth in the British construction industry slowed down in March as companies delayed spending decisions, leading to employment figures rising at their slowest pace since December 2013.The monthly Markit/CIPS UK construction purchasing managers' index released Thursday morning declined 2.3 points in March to 57.8, having reached a four-month high in February, and remained below 61.8, the average for 2014 as a whole.M&S in fashion in Q4Marks & Spencer delivered its first growth from clothing and general merchandise (GM) for 14 quarters, with like-for-like sales unexpectedly rising 0.7% in both clothing and food. The market had been expecting GM sales to fall and food to be flattish. Shares were up 6%.A host of other retailers such as Next, Home Retail, Debenhams, Mothercare, Ted Baker and French Connection were also making gains.UK homewares retailer Dunelm was higher as it delivered a upbeat outlook after increasing sales by 10.7% in the third quarter, though growth did tail off slightly from the first half.Food wholesale retailer Booker also rose after saying it had a "good end to a good year" with a 1% rise in fourth-quarter sales despite ongoing price deflation, as its chairman announced his resignation.The price of iron ore on Thursday plunged below $50 per metric tonne for the first time in over 10 years, as oversupply and lacklustre Chinese demand continue to hound the market. The effect on the UK mining sector was clear with diversified heavyweights BHP Billiton, Glencore and Anglo American all in the red.Playtech's first move into the financial trading market was welcomed by investors as the online gaming group agreed to acquire forex and CFD provider company TradeFX, owner of the markets.com website, for up to €458m.Ingredient and beverage provider Tate & Lyle was higher after reiterating guidance for the current financial year, saying that it expected profit to be lower than initial estimates. Market MoverstechMARK 3,160.35 +0.52%FTSE 100 6,816.03 +0.10%FTSE 250 17,213.71 +0.53%FTSE 100 - RisersMarks & Spencer Group (MKS) 562.50p +6.03%Hikma Pharmaceuticals (HIK) 2,200.00p +3.24%Imperial Tobacco Group (IMT) 3,105.00p +1.97%Coca-Cola HBC AG (CDI) (CCH) 1,246.00p +1.96%Barclays (BARC) 252.65p +1.34%Weir Group (WEIR) 1,715.00p +1.18%London Stock Exchange Group (LSE) 2,470.00p +0.94%WPP (WPP) 1,527.00p +0.93%Associated British Foods (ABF) 2,841.00p +0.89%Standard Life (SL.) 481.60p +0.86%FTSE 100 - FallersBHP Billiton (BLT) 1,441.00p -1.97%Kingfisher (KGF) 361.10p -1.88%easyJet (EZJ) 1,841.00p -1.66%Anglo American (AAL) 1,001.00p -1.52%Antofagasta (ANTO) 723.00p -1.43%Glencore (GLEN) 280.05p -1.43%InterContinental Hotels Group (IHG) 2,613.00p -1.10%Hargreaves Lansdown (HL.) 1,150.00p -1.03%United Utilities Group (UU.) 931.00p -0.90%International Consolidated Airlines Group SA (CDI) (IAG) 595.50p -0.75%FTSE 250 - RisersTelecom Plus (TEP) 951.00p +6.97%BTG (BTG) 783.50p +6.24%Centamin (DI) (CEY) 59.60p +5.30%Rathbone Brothers (RAT) 2,151.00p +4.88%Virgin Money Holdings (UK) (VM.) 429.90p +4.60%Cranswick (CWK) 1,417.00p +3.96%Brewin Dolphin Holdings (BRW) 318.20p +3.31%Zoopla Property Group (WI) (ZPLA) 187.90p +3.07%Genus (GNS) 1,379.00p +2.83%Playtech (PTEC) 798.00p +2.77%FTSE 250 - FallersBetfair Group (BET) 2,178.00p -2.81%Vedanta Resources (VED) 482.90p -2.60%John Laing Infrastructure Fund Ltd (JLIF) 123.50p -2.60%Ladbrokes (LAD) 101.50p -2.59%Kaz Minerals (KAZ) 209.80p -1.82%Electrocomponents (ECM) 237.10p -1.78%JD Sports Fashion (JD.) 477.00p -1.65%Marston's (MARS) 155.70p -1.64%BlackRock World Mining Trust (BRWM) 287.00p -1.37%Lonmin (LMI) 118.60p -1.33%