The FTSE 100 ended 0.5 percent higher after rallying as much as 1 percent with gains capped due to investors shunning defensive stocks, and the midcaps added 0.6 percent.
UK markets joined a global rally sparked by data showing Chinese factory activity grew for the first time in four months in March, as well as hopes of a resolution to a prolonged trade dispute between Washington and Beijing.
Also driving sentiment was a survey that showed UK manufacturing growth at an unexpected 13-month high last month as the country stockpiles for Brexit.
Miners jumped 2.5 percent to a 10-month high as base metals prices rose, including nickel after data suggested stimulus measures in China, the world's biggest nickel consumer, were boosting the economy.
Trade progress and reassurance about the Chinese economy also helped Asia-exposed stocks such as HSBC and StanChart.
"The trade deal is going very well," U.S. President Donald Trump said on Friday, with talks between the world's two largest economies set to resume this week.
The Brexit conundrum continued, with parliament set to vote on different options, and sterling firmed on hopes that the uncertainty will end in a softer Brexit than Prime Minister Theresa May's defeated withdrawal agreement.
The default remains for the UK to fall out of the European Union without a deal on April 12.
All but two sectors in the FTSE 100 were in positive territory, with easyJet's weak trading update the biggest negative.
WPP, the world's biggest advertising group, added 3 percent on its best day in a month after a Deutsche Bank rating upgrade.
EasyJet, by contrast, suffered a 10 percent slump on its worst day in nearly three years after it flagged soft ticket pricing, partly due to Brexit uncertainties.
EasyJet's cautious tone brought down shares in British Airways-owner IAG, Wizz Air and the London-listed shares of Ryanair by between 2 and 4.3 percent.
Defensive stocks, which are deemed safer at times of uncertainty, underperformed. British American Tobacco and Imperial Brands were among the worst fallers, while United Utilities, SSE and National Grid also weakened.
Among midcaps, iron ore pellet producer Ferrexpo jumped 6.3 percent as higher iron ore prices took precedence over the company delaying annual results again, with charity investigation continuing.
Babcock edged 3 percent higher after a media report that Rolls-Royce director and former Shell executive Ruth Cairnie would take over as chairman of the defence contractor.
(Reporting by Yadarisa Shabong and Muvija M, Editing by David Holmes and Ed Osmond)
By Muvija M