The central bank is due to make its announcement at 1200 GMT against the backdrop of soaring prices and supply-chain problems. Equity markets have fully priced in an increase in the Bank Rate to 0.25% from 0.1%, while economists remain split.
The benchmark FTSE 100 index gained 0.3% by 0820 GMT, with miner Glencore, oil major Royal Dutch Shell and telecommunications company BT Group among the best performers.
BT Group added 3.7% after confirming its outlook for this year while reporting a 3% decline in first-half revenue.
The pound weakened as currency markets awaited the BoE’s knife-edge decision, further boosting the export-oriented FTSE 100 index.
The domestically focussed mid-cap index advanced 0.4%.
Britain’s second largest supermarket grocer, Sainsbury’s , fell 3.1% due to uncertainty around its supply chains despite reporting a 23% rise in first-half profit.
