The bank will buy £5 billion worth of bonds every day for 13 weekdays.
In an announcement, the bank said: “Were dysfunction in this market to continue or worsen, there would be a material risk to UK financial stability.
“This would lead to an unwarranted tightening of financing conditions and a reduction of the flow of credit to the real economy,” the Bank of England said.
“In line with its financial stability objective, the Bank of England stands ready to restore market functioning and reduce any risks from contagion to credit conditions for UK households and businesses.”