Blue chip shares shrugged off British Prime Minister Theresa May's announcement on Wednesday (25 January 2017) that the government would publish a White Paper setting out its Brexit plans. The FTSE 100 Index rose by 17.1 points to 7167.4 after May told the Commons she realised there was an appetite among MPs and the country for more details of her administration's approach.

The pound was up by 0.5% against the dollar at $1.2584 (£1, €1.17) and 0.4% higher against the euro at $1.1710.

IG market analyst Joshua Mahony said markets were enjoying "a degree of clarity over the UK's path that has not been seen since June's referendum result".

The owner of Frankie & Benny's was the biggest faller in the second tier after it said it expected a "difficult" six months as the group faced tough competition and rising costs such as a higher national minimum wage.

The Restaurant Group, which owns nearly 500 UK outlets including Garfunkel's and Chiquito, said like-for-like sales fell by 3.9% in the 53 weeks to the start of January 2017, adding that in the final quarter of the year same store sales worsened to a 5.9% decline.

The group said that total sales edged up by 0.9% to £710.7m ($894m) compared with the prior 53 weeks. In the summer of 2016, the group said it would axe 33 sites and begin to revamp its menus in a bid to boost sales.

It admitted it had previously failed to properly test new more expensive menus with customers, which meant that crowd-pleasing dishes such as chicken parmigiana had been mistakenly removed from Frankie & Benny's menus. Restaurant Group shares fell by almost 11%, or 36.7p, to 309.4p.

The biggest afternoon risers in the FTSE 100 Index were Ashtead Group (+46p to 1610p), EasyJet (up 27p to1008p), St James's Place (+28p to1088p), Royal Bank of Scotland (+5.7p to225.7p) and CRH (+68p to 2924p).

The afternoon biggest fallers in the FTSE 100 Index were Vodafone (-5.8p to 193.6p), Kingfisher (-8.1p to 330.7p), Rio Tinto (-64p to 3551p), Randgold Resources (-120p to 6735p) and BHP Billiton (-20.5p to 1460p).

The biggest afternoon risers in the FTSE 250 Index were Ashmore Group (+18.8p to 312p), WH Smith (+91p to 1571p), Ferrexpo (+8p to 148.4p), Aldermore Group (+9p to 219.1p) and McCarthy & Stone (+6.6p to 174p).

The biggest afternoon risers in the FTSE 250 Index were Restaurant (-36.7p to 309.4p), Hochschild Mining (-8.5p to 244.6p), Domino's Pizza (-12.2p to 362.4p), Centamin (-4.7p to 150.1p) and Vectura Group (-2.8p to 132.5p).