The Spanish tendency to add an intrusive e to English words that begin with s[consonant] is well known, as is its consequential effect on the article which leads to people saying an estation, an estatistic etc. Nevertheless, I was surprised the other day to see stablishment in El País. Surely this was a blunder with one of the few English words that really do start with es[consonant].
It turns out not to be so straightforward. According to WordReference the 2005 Espasa-Calpe accepts stablishment, though the DRAE does not, as an alternative to establishment in the limited English sense of the people who run the country:
stablishment o establishment
- (voz i.) m. Conjunto de dirigentes o personas que tienen el poder:
el stablishment de la nación.
A search in El País comes up with four references, the oldest being from March 2009. Does this mean that the word is increasing in use? Anyway it is an unusual phenomenon. We are used to seeing English words Hispanicised, for example esmoquin and esnifar add the intrusive e. But stablishment seems to be a case of hypercorrection that removes an e that really should be there. And, no doubt, it is pronounced el estáblimen!
A final point. The OED accepts stablishment as a variant of establishment in some senses but not the one used in Spanish. Its most recent quotation is from 1898.