LONDON, Dec 20 (Reuters) - Some of Turkey's dollar-denominated government debt saw their biggest falls since March on Monday, along with many bank and corporate bonds, as a rout in the lira showed no sign of let-up.

The Turkish currency's latest slump was triggered by comments from President Tayyip Erdogan on Sunday that his drive for lower interest rates was part of Islamic doctrine.

This also hit bank bonds and corporate credit along with Turkish debt, with almost all the country's bonds due for repayment beyond 2025 down more than 2 cents on the dollar.

Many Turkish bonds due between 2030 and 2045 fell nearly 4 cents on the dollar to their lowest levels since April or May last year.

Turkey's already-record low lira dropped another 11% on Monday. It has now more than halved in value since the central bank started slashing interest rates in September, effectively making it more expensive for the government and firms to repay dollar-denominated debt.

"On a day like today the corporates are almost untradable so it's all about the sovereign debt," said Trium Capital emerging market portfolio manager Peter Kisler.

"Turkey doesn't have a lot of dollar debt (compared to the size of its economy), but if the currency continues like this they will face credit problems at some point," he said, adding that he had given up on trying to "buy the dips" in the lira.

The Turkish President said on Monday that corporate taxes would be cut 1% alongside other measures to help firms and that Turkey would not bow to economic attacks.

By that point bonds issued by state banks Ziraat Bank, Vakif Bank and Halk Bank as well as private banks such as Garanti Bank , Is Bank and Yapi Kredi were down around 2.5%, with most of their share prices 4%-5% lower too.

"It is an absolute blow-up scenario," Himanshu Porwal, an emerging market corporate credit analyst at Seaport Global, said, adding: "Credit always follows the FX... The biggest pain point will be in the bank's subordinated debt."

(Reporting by Marc Jones; Editing by Saikat Chatterjee and Alexander Smith)