Er....fusey I think you'll find that if TGP took into account further tax "credits" the P/E would actually fall, not rise....
So I assume you meant to say if TGP were to operate on a fully taxed basis the P/E would rise.
But this is the real world, not some imaginary one where tax losses don't exist. In the real world TGP do have large tax losses to utilise. So the broker's forecasts incorporate those losses.
And have a look at PBT growth:
Y/E 31/12/04 - £1.457m
Y/E 31/12/05 - £2.18m
Y/E 31/12/06 - £2.65m
Y/E 31/12/07 - £3.71m
Looking at those figures this is a fast-growing business on a very low rating of, I repeat, a forecast historic P/E of less than 6 and a 2006 P/E of around 5.4. Plus any news on the 21st Century CCTV side could lead to a major re-rating to a P/E of, conservatively, 10, and a share price of around 24p.