No they are not local calls . Local and National calls were abolished yonks ago.

The regulator Ofcom made changes in 2009 to 0870  to stop revenue sharing , several landline providers at that time added 0870 numbers as part of their "inclusive" call plans.

If your landline provider doesn't include 0870 numbers in its call plans (or you're making a call outside your plan), then currently depending on your provider charges they would normally be charged the same as 01/02/03 calls, plus the provider's standard call set-up fee. Mobile operators charge more - between 5p and 40p/min.