LONDON (Reuters) – British 20- and 30-year government bonds fell sharply on Wednesday, after the Bank of England for a second day in a row bought no longer-dated bonds at its daily gilt market operation designed to stabilise markets. Thirty-year gilt yields rose as much as 26 basis points (bps) to hit 4.328% at 1429 GMT, their highest since the BoE launched the temporary gilt purchase scheme on Sept. 28 to tame yields which had surged to a 20-year high above 5%. That jump in borrowing costs came after finance minister Kwasi Kwarteng gave a fiscal statement on Sept. 23 which unsettled markets w…