I would start by rejoining the Dublin Regulations, withdrawal from which precipitated the increase in asylum seeking migration to the UK.
Many of these migrants have already had their asylum applications rejected elsewhere by signatory nations to the Dublin Regulations and would therefore have been deported or subject to deportation under those regulations.
Unfortunately, somebody who you wish not to be mentioned, chose to remove the UK from the Dublin Regulations, a huge increase in asylum seeking migration to the UK followed.