The European Central Bank and the U.S. Federal Reserve should overcome their fears about damaging their reputations and buy significant quantities of government bonds to help stimulate their economies, Bank of England policymaker Adam Posen said on Monday.

In an op-ed written for the International Herald Tribune, Posen urged the Fed and the ECB to do more and called for them to team up with governments and come up with a coordinated plan to overcome debt problems.

The right thing to do now is for the Federal Reserve and the European Central Bank to engage in further monetary stimulus... they should buy significant quantities of government securities to help push down long term interest rates and encourage investment, Posen said

In my opinion we can go further, he added. Central banks and governments can engage in forms of coordinated action that will target the burden of past debts that is hanging over the global economy.

(Reporting by Marc Jones; Editing by Toby Chopra)