Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
1912 Bow and Bromley by-election
Table title:
Background
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=2 rowspan=1 > Party </th><th colspan=1 rowspan=1 > Candidate </th><th colspan=1 rowspan=1 > Votes </th><th colspan=1 rowspan=1 > % </th><th colspan=1 rowspan=1 > ± </th></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td class="highlighted"  colspan=1 rowspan=1 > Labour </td><td class="highlighted"  colspan=1 rowspan=1 > George Lansbury </td><td colspan=1 rowspan=1 > 4,315 </td><td class="highlighted"  colspan=1 rowspan=1 > 55.6 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > Conservative </td><td colspan=1 rowspan=1 > Leo Amery </td><td colspan=1 rowspan=1 > 3,452 </td><td class="highlighted"  colspan=1 rowspan=1 > 44.4 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=3 rowspan=1 > Majority </th><td colspan=1 rowspan=1 > 863 </td><td class="highlighted"  colspan=1 rowspan=1 > 11.1 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=3 rowspan=1 > Turnout </th><td colspan=1 rowspan=1 > 7,767 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td colspan=2 rowspan=1 > Labour gain from Conservative </td><th colspan=1 rowspan=1 > Swing </th><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
What candidate won the 1912 Bow and Bromley by-election, which party was he representing, and what majority percentage did he win by?
Answer:
At the 1912 Bow and Bromley by-election, Lansbury had gained the seat for Labour with a majority of 11.1%.