Financial risk management (Tables)

12 Months Ended

Dec. 31, 2017

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Summary of Net Debt Position

The Group’s net debt position is set out below:

All figures in £ millions	2017			2016
Cash and cash equivalents		645			1,459
Marketable securities		8			10
Derivative financial instruments		—			(93	)
Bank loans and overdrafts		(15	)		(39	)
Bonds		(1,062	)		(2,420	)
Finance lease liabilities		(8	)		(9	)
Net debt		(432	)		(1,092	)

Summary of Sensitivity of The Carrying Value of Financial Instruments to Fluctuations in Interest Rates and Exchange Rates

As at 31 December 2017, the sensitivity of the carrying value of the Group’s financial instruments to fluctuations in interest rates and exchange rates is as follows:

All figures in £ millions	Carrying value			Impact of 1% increase in interest rates			Impact of 1% decrease in interest rates			Impact of  10% strengthening in sterling			Impact of 10% weakening in sterling
Investments in unlisted securities		77			—			—			(6	)		7
Cash and cash equivalents		645			—			—			(54	)		66
Marketable securities		8			—			—			—			—
Derivative financial instruments		—			(26	)		26			1			(1	)
Bonds		(1,062	)		45			(48	)		97			(118	)
Other borrowings		(23	)		—			—			2			(2	)
Liability to purchase own shares		(151	)		—			—			—			—
Other net financial assets		497			—			—			(41	)		50
Total financial instruments		(9	)		19			(22	)		(1	)		2

Schedule of Contractual Undiscounted Cash Flows Analysed by Maturity and Currency

The following table analyses the Group’s bonds and derivative assets and liabilities into relevant maturity groupings based on the remaining period at the balance sheet date to the contractual maturity date. The amounts disclosed in the table are the contractual undiscounted cash flows (including interest) and as such may differ from the amounts disclosed on the balance sheet.

	Analysed by maturity												Analysed by currency
All figures in £ millions	Less than one year			Later than one year but less than five years			Five years or more			Total			USD			GBP			Other			Total
At 31 December 2017
Bonds		20			601			533			1,154			184			—			970			1,154
Rate derivatives – inflows		(38	)		(975	)		(684	)		(1,697	)		(53	)		(751	)		(893	)		(1,697	)
Rate derivatives – outflows		48			1,060			667			1,775			1,003			751			21			1,775
Total		30			686			516			1,232			1,134			—			98			1,232
At 31 December 2016
Bonds		82			1,308			1,292			2,682			1,732			—			950			2,682
Rate derivatives – inflows		(103	)		(1,086	)		(867	)		(2,056	)		(239	)		(838	)		(979	)		(2,056	)
Rate derivatives – outflows		82			1,202			891			2,175			1,308			838			29			2,175
Total		61			1,424			1,316			2,801			2,801			—			—			2,801