UK constituencies where at least 1000 people 3 or over speak either Portuguese or Spanish

As a first language, that is. Figures taken from the 2011 Census.

Portuguese

Vauxhall (London), 4800 speakers
Brent Central (London), 4397 speakers
Streatham (London), 3033 speakers
West Ham (London), 2659 speakers
Dulwich and West Norwood (London), 2268 speakers
Tottenham (London), 2219 speakers
Westminster North (London), 1894 speakers
Hampstead and Kilburn (London), 1796 speakers
Bermondsey and Old Southwark (London), 1768 speakers
Cities of London and Westminster (London), 1728 speakers
Camberwell and Peckham (London), 1681 speakers
Peterborough (East of England), 1676 speakers
Hammersmith (London), 1600 speakers
Kensington (London), 1542 speakers
Hackney North and Stoke Newington (London), 1461 speakers
East Ham (London), 1402 speakers
Hackney South and Shoreditch (London), 1278 speakers
Holborn and St Pancras (London), 1270 speakers
Croydon North (London), 1261 speakers
Hendon (London), 1237 speakers
South West Norfolk (East of England), 1190 speakers
Chelsea and Fulham (London), 1176 speakers
Great Yarmouth (East of England), 1155 speakers
Battersea (London), 1132 speakers
Feltham and Heston (London), 1122 speakers
Putney (London), 1099 speakers
Lewisham Deptford (London), 1051 speakers
Oxford East (Southeast England), 1045 speakers
Ealing Central and Acton (London), 1040 speakers
Finchley and Golders Green (London), 1032 speakers
Poplar and Limehouse (London), 1030 speakers
Bethnal Green and Bow (London), 1003 speakers

Spanish

Vauxhall (London), 3183 speakers
Bermondsey and Old Southwark (London), 3109 speakers
Kensington (London), 3018 speakers
Camberwell and Peckham (London), 2995 speakers
Cities of London and Westminster (London), 2615 speakers
Streatham (London), 2473 speakers
Tottenham (London), 2397 speakers
Westminster North (London), 2257 speakers
Hammersmith (London), 2254 speakers
Chelsea and Fulham (London), 2224 speakers
Holborn and St Pancras (London), 1989 speakers
Hackney North and Stoke Newington (London), 1918 speakers
Dulwich and West Norwood (London), 1821 speakers
Hampstead and Kilburn (London), 1777 speakers
Islington South and Finsbury (London), 1751 speakers
Islington North (London), 1684 speakers
Hackney South and Shoreditch (London), 1571 speakers
Bethnal Green and Bow (London), 1492 speakers
Lewisham Deptford (London), 1482 speakers
Hornsey and Wood Green (London), 1466 speakers
Battersea (London), 1457 speakers
Poplar and Limehouse (London), 1436 speakers
West Ham (London), 1371 speakers
Cambridge (East of England), 1269 speakers
Brent Central (London), 1218 speakers
Ealing Central and Acton (London), 1196 speakers
Putney (London), 1158 speakers

In Britain, the majority of Spanish-speakers are from Spain, though there are a number of Latin Americans too (especially Colombians). As for Portuguese-speakers, in most of Britain they come overwhelmingly from Portugal, though in London and a few pockets elsewhere there are many Brazilians and Angolans too.