The Central Bank has set out tougher rules to resolve the deepening mortgage crisis, giving Ireland's main lenders until December to put a debt arrangement in place for 15 per cent of customers more than 90 days in arrears.

Almost 100,000 homeowners are currently more than 90 days behind in repayments, and the banks have until the end of the year to put debt arrangements in place with 14,684 of them.

The banks can write down debt, reschedule the loan, put a new payment plan such as a split mortgage in place or repossess the home.

After discussions with the Troika the Central Bank says it wants to see financial institutions having “concluded arrangements” with 15 per cent of customers in arrears of 90 days or more by the end of December.

The Central Bank is also setting targets for end March 2014 which will require banks to offer sustainable solutions to 70 per cent of customers in arrears of more than 90 days, and concluded solutions to 25 per cent.

This means Irish banks will be required to have concluded deals with 25 per cent of customers, who more than 90 days behind on repayments, by the end of March 2014.

The targets apply to Allied Irish Bank and its subsidiary EBS, Bank of Ireland and its subsidiary ICS, Ulster Bank, KBC, and Permanent TSB.

In March, the Central Bank outlined its initial targets to deal with the mortgage arrears crisis. This included the banks having made offers to 20 per cent of customers by the end of June, to 30 per cent of customers by the end of September and to 50 per cent by the end of this year.

At that time, the regulator stopped short of setting specific targets for concluded agreements between the banks and their customers.

The latest figures from the Central Bank show that 97,894 residential mortgage accounts relating to private dwelling homes were in arrears of 90 days or more at the end of June.