Britain's benchmark FTSE 100 index hit a record high Wednesday as bank stocks gained on renewed speculation of a March rate increase from the U.S. Federal reserve.

The index was marked 95.66 points, or 1.32% higher at 7,359.25 points by 13:30 GMT after breaching the all-time intra-day high of 7,354.14 points set on Jan. 13. Bank stocks were some of the session's biggest gainers, with taxpayer-owned Royal Bank of Scotland (RBS) - Get Royal Bank of Scotland Group plc Sponsored ADR Report rising 2.71% and Barclays plc (BCS) - Get Barclays PLC Sponsored ADR Report advancing 1.56%.

The benchmark was also supported by a weaker sterling, which fell to a 5-week low of 1.2295 against a surging U.S. dollar following President Donald Trump's address to Congress Tuesday and a series of comments from Fed officials, including William Dudley, that suggest a March rate hike is now firmly on the table.

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FTSE 100 constituents earn more than 70% of their revenues outside of the U.K. and the benchmark will normally move in reverse lockstep with declines in the pound.

That said, Britain's mid-cap index, the FTSE 250, also rose to a new all time high after gaining 0.67% to trade at 18,896 points.

Leading the charge among mid-market companies were construction firms CRH (CRH) - Get CRH Plc Sponsored ADR Report and Ashtead (ASHTF) , which had gained 5.4% and 4.4% respectively by the afternoon.

While corporate earnings were a factor, both companies earn more than half their revenues in the U.S. and so have drawn support from Trump having requested support from Congress for a $1 trillion infrastructure spending bill.

CRH takes 51% of sales from America, according to Factset estimates, and reported a 69% increase in full-year profit before tax Wednesday. Meanwhile Ashtead, a construction equipment hire firm, takes 74% of its top line from the U.S.