The FTSE 100 was up 0.4 percent as the dollar strengthened and optimism from the trade talks seen in Asia and on Wall Street spilled over to Europe.

Banks and conumser staples, which make a big chunk of their money abroad, led the gains. Some 70 percent of FTSE 100 constituents make their cash in foreign markets.

Market sentiment was also lifted after US lawmakers struck a tentative agreement to avert another government shutdown and positive noises from Beijing, where officials were hopeful about talks to resolve a protracted trade dispute.

The domestically-focused FTSE 250 added 0.3 percent by 0913 GMT with gains limited by a plunge in Plus500 shares which accounted for a 30-point drop on the index.

Plus500 lost more than a third of its value after the online trading platform forecast 2019 results will be below market expectations, hurt by regulatory crackdown in the European Union on the sale of certain financial products to retail clients.

The stock tanked 38 percent to its lowest in almost a year and dragged rival IG Group down 5.6 percent.

Investors were also cautious ahead of a parliamentary address by Prime Minister Theresa May later in the day as she struggles to seal a Brexit deal.

On the blue chips, miners rose after Goldman Sachs said European commodities and mining equities were "attractively positioned".

Gambling firms rose on news that horse racing in Britain will resume on Wednesday after being halted last week in light of several cases of equine influenza.

Tour operator TUI , which has slumped since a profit warning last week, slipped 8 percent as its first-quarter underlying loss widened.

Small-cap retailer Debenhams shot up 45 percent after it secured additional funding from lenders as it struggles to find a longer-term solution to its financial woes.