Hi. We had a similar problem, 2 1/2 year old and a 4 1/2 year old. We now have a "tag-a-long" on the back for the older one (and i get some help on the hills!) and a Bike Tutor on the front. This works for us although some of our friends have both kids in a burley trailer behind (although they do seem to fight alot!). The tag along is great, especially as we got it on Ebay for next to nothing. Rubbed down, re-painted, rebuilt and it all matches. As for the Bike Tutor we love it, got it on line from their website, our son now rides on it as our daughter had outgrown it when she was 4. Have to say it all works really well and the weight on the front means things are surprisingly stable. Looked at the Tbert and Bo Bike front seats but liked the fact than the Bike Tutor is metal not plastic. This might be easier and more productive than locking horns with a jobs worth in the council. Good luck.