The FTSE 100 was up 0.9% at 6,077.74.
Figures released earlier by the Office for National Statistics showed the number of redundancies in July rose by the most since 2009 as the Covid-19 pandemic took its toll. The data showed 156,000 people were made redundant in the May to July quarter, up 58,000 from the same period a year ago and 48,000 higher than between February and April.
The ONS said these were the largest annual and quarterly increases since 2009.
"While redundancies are at their highest level since September to November 2012, the level remains well below that seen during the 2008 downturn," it said.
Meanwhile, the unemployment rate increased to 4.1% in July from 3.9% the month before. The data showed that the number of employees on payrolls declined by 695,000 in August compared to March and by 36,000 compared to July.
ONS director of economic statistics Darren Morgan said: "Some effects of the pandemic on the labour market were beginning to unwind in July as parts of the economy reopened. Fewer workers were away on furlough and average hours rose. The number of job vacancies continued to recover into August, too.
"Nonetheless, with the number of employees on the payroll down again in August and both unemployment and redundancies sharply up in July, it is clear that coronavirus is still having a big impact on the world of work."
In equity markets, miners were doing well, with Glencore, Rio, BHP and Anglo American all higher after Chinese industrial production and retail sales figures for August surprised to the upside.
Online grocer and technology firm Ocado rallied after it recorded a sharp rise in third-quarter revenue, driven by continued higher average spends as it forecast annual core earnings of £40m.
Insurers RSA and Hiscox gained ground even as the High Court found in favour of claimants on the majority of key issues over insurers failing to pay out business interruption claims due to the Covid-19 crisis.
Next was also in the black after it acquired a majority stake in the UK and Irish arm of L Brands' Victoria's Secret unit for an undisclosed sum as part of a joint-venture agreement.
Polypipe rose as it reported a decline in first-half profit and revenue due to the pandemic but struck a more upbeat note on recent trading.
FirstGroup pushed up after saying it now expects to deliver a small adjusted operating profit for the seasonally-weaker first half of the financial year, ahead of its expectations earlier this summer.
William Hill surged after the bookmaker said a multi-year deal between its US partner Caesars Entertainment and broadcaster ESPN will feature its sports betting apps and sports book odds. Flutter and GVC also rose.
On the downside, Watches of Switzerland slumped after US private equity firm Apollo Global Management sold 33 million shares in the company.
Trainline was also weaker as JPMorgan Cazenove slashed its price target to 387p from 517p and cut its estimates ahead of the company's first-half trading update this week.
FTSE 100 (UKX) 6,077.74 0.85%
FTSE 250 (MCX) 17,758.52 0.46%
techMARK (TASX) 3,873.83 0.64%
FTSE 100 - Risers
Ocado Group (OCDO) 2,483.00p 5.44%
Flutter Entertainment (FLTR) 12,190.00p 3.31%
RSA Insurance Group (RSA) 484.30p 3.04%
Glencore (GLEN) 186.98p 2.94%
Rio Tinto (RIO) 5,136.00p 2.72%
AstraZeneca (AZN) 8,603.00p 2.42%
GVC Holdings (GVC) 904.80p 2.24%
BHP Group (BHP) 1,790.60p 2.12%
Bunzl (BNZL) 2,439.00p 1.96%
Anglo American (AAL) 1,974.20p 1.90%
FTSE 100 - Fallers
Kingfisher (KGF) 271.80p -4.43%
Rolls-Royce Holdings (RR.) 205.10p -2.47%
Informa (INF) 395.80p -1.93%
Standard Chartered (STAN) 375.70p -1.70%
Compass Group (CPG) 1,292.75p -1.58%
International Consolidated Airlines Group SA (CDI) (IAG) 132.50p -1.38%
Avast (AVST) 535.00p -1.11%
Whitbread (WTB) 2,272.00p -0.87%
Barclays (BARC) 102.78p -0.81%
Morrison (Wm) Supermarkets (MRW) 176.25p -0.54%
FTSE 250 - Risers
Hiscox Limited (DI) (HSX) 837.00p 10.39%
William Hill (WMH) 219.50p 10.30%
FirstGroup (FGP) 43.30p 5.87%
Avon Rubber (AVON) 4,200.00p 5.79%
Inchcape (INCH) 482.40p 4.82%
Polypipe Group (PLP) 426.00p 4.41%
Hilton Food Group (HFG) 1,232.00p 4.41%
UK Commercial Property Reit Limited (UKCM) 69.50p 4.35%
Hochschild Mining (HOC) 240.60p 3.80%
Marks & Spencer Group (MKS) 108.50p 3.63%
FTSE 250 - Fallers
Watches of Switzerland Group (WOSG) 313.50p -6.14%
Marshalls (MSLH) 637.50p -5.27%
Trainline (TRN) 375.40p -3.74%
Mitchells & Butlers (MAB) 146.00p -3.44%
Wetherspoon (J.D.) (JDW) 886.50p -3.01%
SSP Group (SSPG) 223.00p -2.62%
Apax Global Alpha Limited (APAX) 166.20p -2.24%
4Imprint Group (FOUR) 2,005.00p -2.20%
Investec (INVP) 138.40p -2.19%
BlackRock Smaller Companies Trust (BRSC) 1,208.00p -2.11%