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* FTSE 100 up 0.5%, FTSE 250 adds 0.4%

* Copper miners lead gains

* JD Sports falls after Barclays downgrades to underweight

* UK election in focus

July 3 (Reuters) - London stocks rebounded on Wednesday, led by a rise in metal miners and renewed hopes of U.S. interest rate cuts, but caution on the eve of UK parliamentary elections capped further gains.

The blue-chip FTSE 100 was up 0.5% after it closed at a more than two-month low on Tuesday, while the mid-cap FTSE 250 added 0.4%, as of 0716 GMT.

U.S. Federal Reserve Chair Jerome Powell on Tuesday said that the country was on a "disinflationary path" but policymakers need more data before cutting interest rates.

His comments bolstered hopes that the central bank will cut rates sooner rather than later.

Industrial metal miners led gains on the benchmark with a 1.8% rise as copper prices ticked higher.

Most sectoral indexes traded higher, with the exception of investment banking and brokerage stocks that fell 0.5%.

Investors, however, exercised caution ahead of UK parliamentary elections, due on Thursday, where Conservatives look set to be replaced after 14 years of power, as per opinion polls.

Keir Starmer and Rishi Sunak kicked off the last day of campaigning before the polls, each warning voters of dire economic consequences if the other man wins.

On the radar now are non-farm payrolls data in the U.S., due on Friday, which will provide more clues on the Fed's monetary policy path.

Among individual stocks, JD Sports sank to the bottom of the FTSE 100 with a 3.7% decline after Barclays downgraded the retailer to "underweight" from "equal-weight".

British tile retailer Topps Tiles dropped 4.2% after it said that challenging market conditions had persisted into the second half of the fiscal year amid weakness in the home repair and sales segments. (Reporting by Purvi Agarwal in Bengaluru; Editing by Sonia Cheema)