From 14 December 2009 all employers will be required to advertise for four weeks if they wish to sponsor an overseas migrant. Previously you had to advertise for two weeks for most positions, or one week where the salary on offer was over £40,000. This requirement does not apply in the case of intra-company transferees.
If an employer has already placed an advertisement prior to 14 December it will come under the old rules and there is no need to re-advertise the position.
Under the new arrangements it will be possible to advertise for an initial two weeks, and then, if no suitable resident worker is found, for a further two weeks at a later stage, provided the advertisement runs for four weeks in total.
Should a suitable applicant be recruited from the resident workforce within the four week period it is not necessary to continue the advertising process for the full four weeks.