Solved Weed. What is it please.

Euphorbia lathyris. aka Caper spurge.

 

Ta. From that I found euphorbia peplus which looks sound bit more like it. This grows like a mini tree.

 

I actually think it's more a sun spurge, euphorbia helioscopia...but a lot of the milkweeds look alike

 

Agree......a weed...Euphorbia helioscopia......common name sun spurge....Leaf shape/margins are correct.

Quote wiki.
"Euphorbia helioscopia.......The leaves are oval, broadest near the tip, 1.5–3 cm long, with a finely toothed margin...pics below.

Euphorbia peplus......The leaves are oval-acute, 1–3 cm (0.4–1.2 in) long, with a smooth margin."

Sorry not right for Euphorbia lathyris.
Quote wiki....."The leaves are arranged in decussate opposite pairs, and are lanceolate, 5–15 cm long and 1-2.5 cm broad, glaucous blue-green with a waxy texture and pale greenish-white midrib and veins"

Be careful ALL Euphorbia have white sap which is toxic.