Blue chip shares closed higher shrugging off moves toward a second Scottish independence referendum in three years.
The FTSE 100 Index lifted 30 points to 7373, after Scottish first minister Nicola Sturgeon confirmed she will ask for permission to hold a fresh referendum on Scottish independence, following the 2014 vote.
Traders were more focused on the effect of the highly anticipated prospect of another US rate hike by the US Federal Reserve on Wednesday.
A higher cost of borrowing in America signals growing confidence in the US economy, but also makes shares in the UK cheaper by comparison.
Spreadex financial analyst Connor Campbell said it was "remarkable how little reaction there has been on the markets" to the Sturgeon announcement.
He added that "investors are seemingly firmly focused on the Fed".
The biggest deal on the markets concerned two FTSE 250 oil services groups as Amec Foster Wheeler agreed to a £2.2bn takeover by Wood Group, bringing together two of the largest UK firms of their type.
Shares in Amec closed almost 12% higher, or 56.8p to 546p, while Aberdeen-based Wood Group's shares lifted more than 1% to 762.5p.
The biggest afternoon risers in the FTSE 100 Index were Fresnillo (+76p to 1436p), Antofagasta (+36.5p to 784.5p), Capita (+23.5p to 568p), Anglo American (+46p to 1186.5p) and Rio Tinto (+126p to 3304.5p).
The biggest afternoon fallers in the FTSE 100 Index were BT (-11p to 331.6p), Standard Life (-8.5p to 371.5p), BP (-7.2p to 463.5p), Royal Bank of Scotland (-3.7p to 241.3p) and Unilever (-46p to 3989.5p).
The biggest afternoon risers in the FTSE 250 Index were Hochschild Mining (+28p 266p), Amec Foster Wheeler (+56.8p to 546p), Bovis Homes (+82.5p to 910.5p), Kaz Minerals (+24p to 478.7p) and Centamin (+8.5p to 171p).
The biggest afternoon fallers in the FTSE 250 Index were Homeserve (-37p to 523p), Evraz (-11.6p to 201.4p), Domino's Pizza (-15p to 331.6p), AA (-9.8p to 261.7p) and Sophos Group (-9.7p to 270.2p).