The FTSE 100 has hit its highest point since June 2015, reaching 6,974 points in morning trading, up 1.09 per cent at time of writing.
A weaker pound has helped to edge the UK's benchmark stocks upwards, moving ever closer to that psychologically significant 7,000 mark. Many of the international blue-chips on the index will benefit from increased foreign revenues as the pound falls.
But sterling plummeted below $1.29 this morning after Prime Minister Theresa May said yesterday Article 50 will be triggered by March 2017. She also signalled she will prioritise taking back control of Britain's borders over getting access to the EU single market.
The FTSE 250, meanwhile, was up one per cent at 18,050.
This morning, chancellor Philip Hammond said: "We must expect some turbulence as we go through this negotiating process.
"We need to support the economy to make sure than consumer confidence remains."
In a speech at the Conservative party conference today, he is expected to say he will move away from George Osborne's fiscal policies because Britain needs a "new plan".