27. Trade and other payables

(in millions of euros)	December 31, 2016	December 31, 2015
Advance payments received for work in progress	4	4
Trade payables	239	227
Current portion of deferred credits	40	10
Other taxes and social security charges	83	101
Other liabilities	461	464
Accrued expenses and deferred income	196	254
Total	1,023	1,060

The accrued expenses and deferred income include the monies received in the context of the FENS agreement (fund for one-off contributions). At the end of 2012, NS received a sum from ProRail as a consequence of the addendum to the FENS framework agreement. The total outstanding liability (€30 million) has been allocated through project-related decisions. About €10 million of the amount in this item is expected to have a term of more than one year.

The trade and other payables include an amount of €16 million (€13 million in 2015) that concerns related parties (ProRail and government).

The Group's liquidity risk due to trade and other payables is stated in note 30.

For more detailed information about the sums received in advance for work in progress, see note 18.