R,
Note you are close to the h rate limits though and any other income that falls within the "untaxed tax free" savings or dividend allowance could put you over the top even though that income would probably not specifically generate a tax charge itself.
A quick point about the interaction between the TTA and the so-called Savings and Dividend "Allowances": they are not treated in similar fashion. By which I mean that if one hopes not to be a Higher Rate taxpayer by hiding behind the Dividend "Allowance", then tough but not so with the Savings "Allowance": if one slides above what would otherwise be the Higher Rate Threshold by virtue of the Savings "Allowance" alone, then that does not preclude eligiblity either to elect or to benefit from the election.
(ITA 2007 s 55B (2)(ba) in relation to the Dividend "Allowance", no equivalent condition for the Savings "Allowance"; ITA 2007 s 55C(1)(ca); beneficiary/elector respectively).
This distinction derives from a time when the Dividend "Allowance" was £5k, and the Savings "Allowance" was no more than £1k.
Best wishes,
Lambs