Tbf, I think we have receded significantly from the 1m legal migration figure - is it 5/600 000 now - it does make the illegal immigration ratio look all the more startling now.
I have no idea what they'll do. What they should do is reduce taxation cliff edges, take their foot off the neck of businesses and drastically cut state dependency.
But, re tax hikes, I doubt they'd be willing to take a political hit of reducing the value of working against the value living entirely on benefits even further, so I think that taxation burden will fall outside of basic rate.